MLA

Bernstein, Leonard. The Unanswered Question: Six Talks At Harvard. 13th ed. Cambridge MA: Harvard University Press, 2002.

APA

Bernstein, L. (2002). The Unanswered Question: Six Talks at Harvard. 13th ed. Cambridge MA: Harvard University Press.

Chicago

Bernstein, Leonard The Unanswered Question: Six Talks At Harvard. 13th ed. Cambridge MA: Harvard University Press, 2002.