Northern Nigeria (Nigeria). Ministry of Health. Annual report of the Ministry of Health, Northern Nigeria. Govt. Printer.
Παραπομπή σε μορφή Chicago (17η εκδ.)Northern Nigeria (Nigeria). Ministry of Health. Annual Report of the Ministry of Health, Northern Nigeria. Kaduna: Govt. Printer.
Παραπομπή σε μορφή MLA (8th εκδ.)Northern Nigeria (Nigeria). Ministry of Health. Annual Report of the Ministry of Health, Northern Nigeria. Govt. Printer.
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