Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Pyotr Mikhaylovich Yershov (Russian: Пётр Миха́йлович Ершо́в, 1910–1994) was a Soviet theater director and art theoretician, most famous for his textbooks on directing and works on Stanislavski's system.
He wrote Directing as a Practical Psychology, with forewords by Oleg Yefremov and P.V. Simonov, 1972, and Technology of an Actor in 1959, that is often recommended course material in Russian and American theater schools.