Παραπομπή APA

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

Παραπομπή Chicago Style

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

Παραπομπή MLA

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