Heady, E. O., & Srivastava, U. K. (1975). Spatial sector programming models in agriculture. Iowa State university.
Cita Chicago (17th ed.)Heady, Earl O., i Uma K. Srivastava. Spatial Sector Programming Models in Agriculture. Ames: Iowa State university, 1975.
Cita MLA (9th ed.)Heady, Earl O., i Uma K. Srivastava. Spatial Sector Programming Models in Agriculture. Iowa State university, 1975.
Atenció: Aquestes cites poden no estar 100% correctes.