Jean-Philippe, the drawings by Mikheev in Polygon book are very early and not very accurate drawings, but they were the base for all recently published drawings of Flanker.

The common opinion is that the best available publically drawings are by "Glazkov" (pseudonumus) published in Aviatsia i Vremya magazine #3, 2003.

You can find them at http://www.airwar.ru/other/draw/su27aiv.html

Rgds

Sergey