On genus expansion of knot polynomials and hidden structure of Hurwitz tau-functions A. Mironov, A. Morozov and A. Sleptsov Eur. Phys. J. C, 73 7 (2013) 2492 Published online: 06 July 2013 DOI: 10.1140/epjc/s10052-013-2492-9