Gruber, E., & Jędra, A. (2000). Tajny świat parapsychologii. "Amber".
Chicago Style (17th ed.) CitationGruber, Elmar, and Anna Jędra. Tajny świat Parapsychologii. Warszawa: "Amber", 2000.
MLA (9th ed.) CitationGruber, Elmar, and Anna Jędra. Tajny świat Parapsychologii. "Amber", 2000.
Warning: These citations may not always be 100% accurate.