Cita APA (7th ed.)

Ullmann, F., & Elvers, B. (2013). Ullmann's renewable resources. Wiley-VCH.

Cita Chicago (17th ed.)

Ullmann, Fritz, i Barbara Elvers. Ullmann's Renewable Resources. Weinheim: Wiley-VCH, 2013.

Cita MLA (9th ed.)

Ullmann, Fritz, i Barbara Elvers. Ullmann's Renewable Resources. Wiley-VCH, 2013.