Wittgenstein, L. (1965). Preliminary studies for the 'Philosophical investigations': Generally known as the Blue and Brown books. New York: Harper & Row.
Чикагска система за цитиранеWittgenstein, Ludwig. Preliminary Studies for the 'Philosophical Investigations': Generally Known As the Blue and Brown Books. New York: Harper & Row, 1965.
MLA формат за цитиранеWittgenstein, Ludwig. Preliminary Studies for the 'Philosophical Investigations': Generally Known As the Blue and Brown Books. New York: Harper & Row, 1965.
Внимание: Тези цитати може да не са 100% точни.