Complex sentence: During the 1990s, Bodrov read a book by Russian historian Lev Gumilev entitled "The Legend of the Black Arrow", which offered a more disciplined view of the Mongol leader and influenced Bodrov to create a film project about the warrior.
Split into simpler sentences: During the 1990s, Bodrov read a book by Russian historian Lev Gumilev entitled "The Legend of the Black Arrow". Gumilev's book offered a more disciplined view of the Mongol leader which influenced Bodrov to create a film project about the warrior.