APA

Peterson G. a., Unger P. W. & Payne W. a. (2006). Dryland agriculture = Agricultura de secano / G.A. Peterson, P.W. Unger, W.A. Payne. Madison: Soil Science Society of America.

Chicago

Peterson Gary a, Unger Paul W and Payne William a. 2006. Dryland agriculture = Agricultura de secano / G.A. Peterson, P.W. Unger, W.A. Payne. Madison: Soil Science Society of America.

Harvard

Peterson G. a., Unger P. W. and Payne W. a. (2006). Dryland agriculture = Agricultura de secano / G.A. Peterson, P.W. Unger, W.A. Payne. Madison: Soil Science Society of America.

MLA

Peterson Gary a, Unger Paul W and Payne William a. Dryland agriculture = Agricultura de secano / G.A. Peterson, P.W. Unger, W.A. Payne. Madison: Soil Science Society of America. 2006.