Some poets and writers use very unusual rhymes. Well-known examples are in the song lyrics to the 1939 MGM film version of L. Frank Baum's "The Wizard of Oz". The lyrics, written by E. Y. "Yip" Harburg, use many odd rhymes, plus internal rhymes, complex rhyme patterns, and other tricks of language. W. S. Gilbert, the lyricist for the Gilbert and Sullivan comic operas, wrote the same way. The books of Dr. Seuss are also famous for their many strange rhymes.