Não informado. (1950). Alex L. du Toit Memorial Lectures. Geological Society of South Africa.
Chicagoスタイル(17版)引用形式Não informado. Alex L. Du Toit Memorial Lectures. Johannesburg, Africa do Sul: Geological Society of South Africa, 1950.
MLA(8版)引用形式Não informado. Alex L. Du Toit Memorial Lectures. Geological Society of South Africa, 1950.
警告: この引用は必ずしも正確ではありません.