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42. The trigonometric Grassmannian  and a difference $W$-algebra, Glasgow Math. J., Volume 51, pp 95-106  2009. (with L.Haine and P. I Iliev)
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44. (with Mihajlova A)  An improved estimate for the number of zeros of Abelian integrals for cubic Hamiltonians  {\bf NONLINEARITY} Volume: 23 Issue: 12 Pp. 3053-3069    2010 .

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