APA (7th ed.) Citation

Grallert, W., & Gruschke, W. (1971). Lexikon der Philatelie. Hörnemann.

Chicago Style (17th ed.) Citation

Grallert, Wolfram, and Waldemar Gruschke. Lexikon Der Philatelie. Bonn: Hörnemann, 1971.

MLA (9th ed.) Citation

Grallert, Wolfram, and Waldemar Gruschke. Lexikon Der Philatelie. Hörnemann, 1971.

Warning: These citations may not always be 100% accurate.