question: What was the name of the book Wittgenstein published in 1921 ?
answer: Wittgenstein 's Tractatus Logico-Philosophicus
turker_answer: The name of the book Wittgenstein published in 1921 was Wittgenstein 's Tractatus Logico-Philosophicus .
rule-based: The name of the book Wittgenstein published in 1921 was Wittgenstein 's Tractatus Logico-Philosophicus .