Kellogg, Charles (February 1933). "A Method for the Classification of Rural Lands for Assessment in Western North Dakota". The Journal of Land & Public Utility Economics. 9 (1): 12. doi:10.2307/3138756. JSTOR3138756.
jstor.org
Kellogg, Charles (February 1933). "A Method for the Classification of Rural Lands for Assessment in Western North Dakota". The Journal of Land & Public Utility Economics. 9 (1): 12. doi:10.2307/3138756. JSTOR3138756.