Complex sentence: In 1999, Farrar, Straus and Giroux published what is arguably Anderson's most famous novel so far, "Speak", which won numerous awards and was a "The New York Times" best seller.
Split into simpler sentences: In 1999, Farrar, Straus and Giroux published what is arguably Anderson's most famous novel so far, "Speak". It won numerous awards and was a "New York Times" best seller.