Παραπομπή APA

Spangenberg, K. R. (1948). Vacuum tubes. McGraw-Hill Book Co..

Παραπομπή Chicago Style

Spangenberg, Karl R. Vacuum Tubes. New York: McGraw-Hill Book Co., 1948.

Παραπομπή MLA

Spangenberg, Karl R. Vacuum Tubes. McGraw-Hill Book Co., 1948.