1. A. Cahours, Untersuchungen űber die metallhaltigen organischen Radicale (Investigation of Organometallic Compounds), Annal. Chem. Pharm., 1862, 122, p 329-347, in German (Equi Diagram; Experimental)
2. E.A. Letts and N. Collie, On the Actions of Haloid Compounds of Hydrocarbon Radicals on Phosphide of Sodium and on the Salts of Tetrabenzyl-Phosphonium, Proc. Roy. Soc. Edinburgh, 1881, 11, p 46-50 (Equi Diagram; Experimental)
3. A. Joannis, Action du phosphore d’hydrogène sur le potassammonium et le Sodammonium (Action of PH3 on Potassium and Sodium in Liquid Ammonia), Compt. Rend. Hebd. Séances Acad. Sci., 1894, 119, p 5657-559, in French (Equi Diagram; Experimental)
4. C. Hugot, Sur quelques phosphures alcalins (Some Alkali Phosphides), Compt. Rend. Hebd. Séances Acad. Sci., 1895, 121, p 206-208, in French (Equi Diagram; Experimental)
5. L. Hackspill and R. Bossuet, Sur de nouveaux phosphures alcalins P5M2 (New Alkali Phosphides P5M2), Compt. Rend. Hebd. Séances Acad. Sci., 1912, 154, p 209-211, in French (Equi Diagram; Experimental)