Cita APA (7a ed.)

Hellman, H. (1973). The city in the world of the future. Ladder.

Cita Chicago Style (17a ed.)

Hellman, Hal. The City in the World of the Future. s.l.: Ladder, 1973.

Cita MLA (8a ed.)

Hellman, Hal. The City in the World of the Future. Ladder, 1973.