입문【入門】
начало изучения; введение в курс
入門하다 поступать в ученики; начинать изучение чего
입문서【入門書】
(учебное) пособие
"The more things change, the more they are the same." Alphonse Karr
"Everything that is beautiful and noble is the product of reason and calculation." Charles Baudelaire
"The best way to keep your friends is not to give them away." Wilson Mizner
"Silence is the mother of truth." Benjamin Disraeli