Não informado. (1959). Bulletin of the Geophysical Observatory. Haile Selassie i University.
Chicagoスタイル(17版)引用形式Não informado. Bulletin of the Geophysical Observatory. Addis Ababa: Haile Selassie i University, 1959.
MLA(8版)引用形式Não informado. Bulletin of the Geophysical Observatory. Haile Selassie i University, 1959.
警告: この引用は必ずしも正確ではありません.