North east Nigeria 1:1,000,000.
Great Britain.Directorate of Overseas Surveys.
Aitchison, Peter John.Land resources of north east Nigeria.
[Tolworth] : Directorate of Overseas Surveys,
1971.
Includes legend.
To accompany: The land resources of north east Nigeria, Vol. 1: The environment/ by P.J. Aitchison ... [et al.].
Phytogeography
Vegetation mapping