Singh, G. S. (1985). The negative exponential model: A synthesis of rank, gravity, and entropy functions in urban geography. Govind Ballabh Pant Social Science Institute.
Lua i Stíl Chicago (17ú heag.)Singh, Govind Saran. The Negative Exponential Model: A Synthesis of Rank, Gravity, and Entropy Functions in Urban Geography. Allahabad: Govind Ballabh Pant Social Science Institute, 1985.
Lua MLA (8ú heag.)Singh, Govind Saran. The Negative Exponential Model: A Synthesis of Rank, Gravity, and Entropy Functions in Urban Geography. Govind Ballabh Pant Social Science Institute, 1985.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.