Cita APA (7a ed.)

Ewald, W. R. (1970). Environment and policy: The next fifty years. Indiana university press.

Cita Chicago Style (17a ed.)

Ewald, William R. Environment and Policy: The Next Fifty Years. Bloomington: Indiana university press, 1970.

Cita MLA (9a ed.)

Ewald, William R. Environment and Policy: The Next Fifty Years. Indiana university press, 1970.