Bekhtereva, N. P. (1990). Per aspera--: Zhiznʹ, nauka o mozge cheloveka, zhiznʹ. "Nauka," Leningradskoe otd-nie.
Dyfyniad Arddull ChicagoBekhtereva, N. P. Per Aspera--: Zhiznʹ, Nauka O Mozge Cheloveka, Zhiznʹ. Leningrad: "Nauka," Leningradskoe otd-nie, 1990.
Dyfyniad MLABekhtereva, N. P. Per Aspera--: Zhiznʹ, Nauka O Mozge Cheloveka, Zhiznʹ. "Nauka," Leningradskoe otd-nie, 1990.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.