Leffler, G. L. (1949). Average prices of gas, water and electric light and power companies in Pennsylvania since 1939.
Chicago-Zitierstil (17. Ausg.)Leffler, George Leland. Average Prices of Gas, Water and Electric Light and Power Companies in Pennsylvania Since 1939. State College, Pa, 1949.
MLA-Zitierstil (8. Ausg.)Leffler, George Leland. Average Prices of Gas, Water and Electric Light and Power Companies in Pennsylvania Since 1939. 1949.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.