1. A study of soil conditions within some land facets in the savanna zone of Nigeria;Ameyan,1984
2. A review of land facets as soil mapping units with particular reference to the Land Resources Division survey of the soils of the Western State, Savanna, Nigeria;Areola;Savanna,1977
3. Soil variability within land facets in areas of low, smooth relief: a case study of the Gwagwa plains, Nigeria;Areola;Soil Survey and Land Evaluation,1982
4. Field trials of terrain classification—statistical procedure;Beckett,1965
5. Soil variability;Beckett;Soils Fertil.,1971