E. A. Belenkov, A. E. Kochengin, “Structure and electronic properties of crystals consisting of graphene layers $L_6$, $L_{4-8}$, $L_{3-12}$, and $L_{4-6-12}$”, Fizika Tverdogo Tela, 57:10 (2015), 2071–2078; Phys. Solid State, 57:10 (2015), 2126–2133
