APA (7th ed.) Citation

Babson, R. W. (1948). Looking ahead fifty years (Rev. ed.). Harper.

Chicago Style (17th ed.) Citation

Babson, Roger Ward. Looking Ahead Fifty Years. Rev. ed. New York: Harper, 1948.

MLA (9th ed.) Citation

Babson, Roger Ward. Looking Ahead Fifty Years. Rev. ed. Harper, 1948.