Tzschichhold, H. (1991). Eulenspiegels Postkartenkalender 1991. Eulenspiegel.
Cita Chicago (17th ed.)Tzschichhold, Hans-Werner. Eulenspiegels Postkartenkalender 1991. Berlin: Eulenspiegel, 1991.
Cita MLA (8th ed.)Tzschichhold, Hans-Werner. Eulenspiegels Postkartenkalender 1991. Eulenspiegel, 1991.
Atenció: Aquestes cites poden no estar 100% correctes.