IGU Working Group on Mathematical Models, Fischer, M. M., Nijkamp, P., & Papageorgiou, Y. Y. (1990). Spatial choices and processes. North-Holland Distributors for the U.S. and Canada, Elsevier Science Pub. Co.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रIGU Working Group on Mathematical Models, Manfred M. Fischer, Peter Nijkamp, और Y. Y. Papageorgiou. Spatial Choices and Processes. Amsterdam, New York, New York, N.Y., U.S.A: North-Holland Distributors for the U.S. and Canada, Elsevier Science Pub. Co, 1990.
एमएलए (9वां संस्करण) प्रशस्ति पत्रIGU Working Group on Mathematical Models, et al. Spatial Choices and Processes. North-Holland Distributors for the U.S. and Canada, Elsevier Science Pub. Co, 1990.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.