Cita APA

Tyagi, A., & Sing, V. UGC NET/SET environment science. Danika.

Chicago Edition Citation

Tyagi, Anil, i Virendra Sing. UGC NET/SET Environment Science. 2011: Danika.

Cita MLA

Tyagi, Anil, i Virendra Sing. UGC NET/SET Environment Science. Danika.