Complex sentence: Many of the Kleks books and plot points were made into a series of films in the 1980s, while the poem "Pchła Szachrajka" ("Adventures of a Cheating Flea") was developed into an animated film in 1989.
Split into simpler sentences: Many of the Kleks books and plot points were made into a series of films in the 1980s. While a poem "Pchła Szachrajka" ("Adventures of a Cheating Flea") was developed into an animated film in 1989.