G. Nikolov, A comparison theorem in the theory of quadrature formulas, Math. Balkanica 2, 1(1988), 3-10.
G. Nikolov and R. Uluchev, A comparison theorem for Tchebysheff polynomials, Serdica 14 (1988), 95-97.
G. Nikolov, Existence and uniqueness of Hermite-Birkhoff Gaussian quadrature formulae, Calcolo 26 (1989), 41-59.
B. Bojanov and G. Nikolov, Comparison of Birkhoff type quadrature formulae, Math. Comp. 54 (1990), 627-648.
G. Nikolov, On the monotonicity of sequences of quadrature formulae, Numer. Math. 62 (1992), 557-565
G. Nikolov, Gaussian quadrature formulae for splines. В : "Numerische Integration, IV" (G. Hämmerlin and H. Brass Eds.), ISNM 112, 267-281, Birkhäuser, Basel, 1993.
G. Nikolov, Exit criteria and monotonicity of the remainders of Euler-MacLaurin quadrature formulae. В: "Open Problems in Approximation Theory" (B. Bojanov Ed.), 156-162, SCT Publishing, Singapore, 1994.
P. Köhler and G. Nikolov, Error bounds for Gauss type quadrature formulae related to spaces of splines with equidistant knots, J. Approx. Theory 81 (1995), 368-388.
P. Köhler and G. Nikolov, Error bounds for optimal definite quadrature formulae, J. Approx. Theory 81 (1995), 397-405.
G. Nikolov, On certain definite quadrature formulae, J. Comp. Appl. Math. 75 (1996), 329-343.
B. Bojanov and G. Nikolov, Duffin and Schaeffer type inequality for ultraspherical polynomials, J. Approx. Theory 84 (1996), 129-138.
L. Milev and G. Nikolov, On the inequality of I. Schur, J. Math Anal. Appl. 216 (1997), 421-437.
G. Nikolov, On the remainder of the Gauss-Lobatto quadrature formula associated with the second Chebyshev weight function B: Proceedings of the Sixth International Colloquium on Numerical Analysis and Computer Science with Applications, August 13-17, 1997, Plovdiv, Bulgaria (E. Minchev Ed.), Academic Publications, 137-144.
G. Nikolov, On certain Duffin and Schaeffer type inequalities, J. Approx. Theory 93 (1998), 157-176.
K.-J. Förster, P. Köhler and G. Nikolov, Monotonicity and stopping rules for compound Gauss-type quadrature formulae, East J. Approx. 4 (1998), 55-74.
G. Nikolov, An inequality of Duffin-Schaeffer-Schur type, Annuaire Univ. Sofia 90 (1998), 109-123.
D.B. Hunter and G. Nikolov, Gaussian quadrature of Chebyshev polynomials, J. Comp. Appl. Math. 94 (1998), 123-131.
G. Nikolov, An inequality for polynomials with elliptic majorant, J. Inequal. Appl. 4 (1999), 315-325.
B. Bojanov, D. Dryanov, W. Haussmann and G. Nikolov, Best one-sided L1-approximation by blending functions. В: Advances in Multivariate Approximation (W. Haussmann, K. Jetter and M. Reimer Eds.), Math. Research v. 107, ISBN 3-527-40236-5, Wiley - VCH, Berlin 1999, 85-106.
D.B. Hunter and G. Nikolov, Gegenbauer weight functions admitting L2 Duffin and Schaeffer type inequalities, B: Applications and computation of orthogonal polynomials (W. Gautschi, G. Golub and G. Opfer, eds.), Birkhäuser, Basel, 1999, ISNM 131, 121-131.
D.B. Hunter and G. Nikolov, On the error term of symmetric Gauss-Lobatto quadrature formulae for analytic functions, Math. Comp. 69 (2000), 269-282.
B. Bojanov, W. Haussmann and G. Nikolov, Bivariate polynomials of least deviation, Canad. J. Math. 53 (3) (2001), 489-505.
G. Nikolov, Inequalities of Duffin-Schaeffer type, SIAM J. Math. Anal. 33 (3) (2001), 686-698.
G. Nikolov, On the weights of nearly Gaussian quadrature formulae, East J. Approx. 7 (2001), 115-120.
V. Gushev and G. Nikolov, On some cubature formulae using mixed type data. В: Recent Progress in Multivariate Approximation (W. Haussmann, K. Jetter and M. Reimer, Eds.), ISNM 137, Birkhäuser, Basel, 2001, 163-184.
G. Nikolov, Snake polynomials and Markov-type inequalities, B: Approximation Theory: a volume dedicated to Blagovest Sendov (B. Bojanov, Ed.), Darba, Sofia, 2002, 342-352.
G. Nikolov, The Christoffel function for the Hermite weight is bell-shaped, J. Approx. Theory 125 (2) (2003), 145-150.
G. Nikolov, Markov-type inequalities in the L2-norms induced by the Tchebysheff weights, Arch. Ineq. Appl. 1 (2003), 361-376.
G. Nikolov, An extremal property of Hermite polynomials, J. Math. Anal. Appl. 290 (2004), 405-413.
G. Nikolov and R. Uluchev, Inequalities for real-root polynomials. Proof of a conjecture of Foster and Krasikov, в: Approximation Theory: A volume dedicated to Borislav Bojanov (D.K. Dimitrov, G. Nikolov, and R. Uluchev, Eds.) , Prof. Marin Drinov Academic Publ. House, Sofia 2004, 201-216.
G. Nikolov, An extension of an inequality of Duffin and Schaeffer, Constr. Approx. 21 (2005), 181-191.
G. Nikolov, Inequalities of Duffin-Schaeffer type, II, East J. Approx. 11 (2) (2005), 147-168.
G. Nikolov, An extension of an inequality of I. Schur, Math. Nachr. 278 (10) (2005).
G. Nikolov, Polynomial inequalities of Markov and Duffin-Schaeffer type. В: Constructive theory of functions. Varna 2005 (B. Bojanov, ed.), Prof. Marin Drinov Academic Publ. House, Sofia, 2006, 201-246.
V. Gushev and G. Nikolov, Formulae for calculation of normal probability, NMA 2006 (T. Boyanov et al., Eds.), Lecture Notes in Computer Sciences, Springer-Verlag 2140 (2007), 369-377.
G. Nikolov, Cubature formulae for the disk using Radon projections, East J. Approx. 14, 4(2008), 401-410.
V. Gushev and G. Nikolov, Modified product cubature formulae, J. Comp. Appl. Math. 224 (2009), 465-475.
G. Nikolov and C. Simian, Gauss-type quadrature formulae for parabolic splines with equidistant knots. В: Approximation and Computation - In Honor of Gradimir V. Milovanovic, pp. 207 - 229 (W. Gautschi, G. Mastroianni, Th. M. Rassias, eds.), Springer Optimization and its Applications, Springer Verlag, Berlin - Heidelberg - New York, 2010.
D. K. Dimitrov and G. Nikolov, Sharp bounds for the extreme zeros of classical orthogonal polynomials, J. Approx. Theory 162 (10) (2010), 1793-1804
G. P. Nikolov and P. B. Nikolov, Quadrature formulae based on interpolation by parabolic splines, East J. Approx. 16, 3(2010), 219-233.
G. Nikolov and A. Alexandrov, An inequality of Duffin-Schaeffer type for Hermite polynomials, в: Constructive Theory of Functions, Sozopol 2010 (G. Nikolov and R. Uluchev, Eds.), Prof. Marin Drinov Academic Publ. House, Sofia, 2012, 9-20.
G. Nikolov and A. Shadrin, On Markov-Duffin-Schaeffer inequalities with a majorant, в: Constructive Theory of Functions, Sozopol 2010 (G. Nikolov and R. Uluchev, Eds.), Prof. Marin Drinov Academic Publ. House, Sofia, 2012, 227-264.
G. Nikolov and A. Alexandrov, On the behavior of Gegenbauer polynomials in the complex plane, Results in Mathematics, 62 (2012), 415-428, DOI 10.1007/s00025-012-284-4.
A. Avdzhieva and G. Nikolov, Numerical computation of Gaussian quadrature formulae for spaces of cubic splines with equidistant knots, в: Proceedings of BGSIAM'2012, ISSN: 1314-7145, 28-39.
G. Nikolov, Inequalities of Markov-Duffin-Schaeffer type with a majorant, Sofia University "St. Kliment Ohridski", Research Excellence 2008-2013, St. Kliment Ohridski University Press, Sofia, 2013, pp. 43-44.
G. Nikolov, On Turan's inequality for ultraspherical polynomials, Ann. Univ. Sofia 101 (2013), 105-114.
A. Avdzhieva and G. Nikolov, On certain asymptotically optimal quadrature formulae, в: Advanced Research in Mathematics and Computer Science (P. Sloup, K. Stefanov, I. Koychev and P. Boytchev, Eds.), St. Kliment Ohridski University Press, Sofia, 2014, pp. 3-21.
G. Nikolov, Inequalities for ultraspherical polynomials. Proof of a conjecture of I. Rasa, J. Math. Anal. Appl. 418 (2014), 852-860.
G. Nikolov and A. Shadrin, On Markov-Duffin-Schaeffer inequalities with a majorant, II, в: Constructive Theory of Functions, Sozopol 2013 (K. Ivanov, G. Nikolov and R. Uluchev, Eds.), Prof. Marin Drinov Academic Publ. House, Sofia, 2014, pp. 175-197.
A. Alexandrov, H. Dietert, G. Nikolov and V. Pillwein, Proof of a conjecture of M. Patrick concerning Jacobi polynomials, J. Math. Anal. Appl. 428 (2015), 750-761.
G. Nikolov and V. Pillwein, An extension of Turan's inequality, Math. Inequal. Appl. 18 (1) (2015), 321-335, doi: 10.7153/mia-18-22.