Citação norma APA

Leffler, G. L. (1949). Average prices of gas, water and electric light and power companies in Pennsylvania since 1939.

Citação norma Chicago

Leffler, George Leland. Average Prices of Gas, Water and Electric Light and Power Companies in Pennsylvania Since 1939. State College, Pa, 1949.

Citação norma MLA

Leffler, George Leland. Average Prices of Gas, Water and Electric Light and Power Companies in Pennsylvania Since 1939. 1949.

Nota: a formatação da citação pode não corresponder 100% ao definido pela respectiva norma.