F. Asinger; H. Offermanns. Syntheses with ketones, sulfur, and ammonia or amines at room temperature. Angewandte Chemie International Edition in English. 1967, s. 907–919. DOI10.1002/anie.196709071.
Karlheinz Drauz; Hans Günter Koban; Jürgen Martens; Wolfgang Schwarze. Phosphonic and Phosphinic Acid Analogs of Penicillamine. Liebigs Annalen der Chemie. 1985-03-12, s. 448–452. DOI10.1002/jlac.198519850303.