MLA

Girish Shukla, Ajit Varma, Girish Shukla, and Ajit Varma. Soil Enzymology. Springer Berlin Heidelberg, 2011.

APA

Girish Shukla, A. Varma, Shukla, G., & Varma, A. (2011). Soil Enzymology. Springer Berlin Heidelberg.

Chicago

Girish Shukla, Ajit Varma, Girish Shukla, and Ajit Varma. Soil Enzymology. : Springer Berlin Heidelberg, 2011.