APA-referens (7:e uppl.)

Heady, E. O., & Srivastava, U. K. (1975). Spatial sector programming models in agriculture. Iowa State university.

Chicago-referens (17:e uppl.)

Heady, Earl O., och Uma K. Srivastava. Spatial Sector Programming Models in Agriculture. Ames: Iowa State university, 1975.

MLA-referens (9:e uppl.)

Heady, Earl O., och Uma K. Srivastava. Spatial Sector Programming Models in Agriculture. Iowa State university, 1975.