1. M. Sabatier, “Thermochemical Measurements on Sulfides,≓Ann. Chim. Phys. 5thSer., 22, 5–98 (1881)in French. (Equi Diagram, Thermo ; Experimental)
2. C. Hugot, “Action of Na and K on Se in Liquid Ammonia,≓C.R. Hebd. Séances Acad. Sci., 129, 388–390 (1889) in French. (Equi Diagram; Experimental)
3. W.P. Bloxam, “Hydrosulfides, Sulfides and Polysulfides of K and Na,≓Trans. Chem. Soc, 77,753–770 (1900). (Equi Diagram; Experimental)
4. C. Hugot, “Action of Na and K on Some Metalloids in Liquid Ammonia,≓Ann. Chim. Phys. 7th Ser, 21, 5–87 (1900) in French. (Equi Diagram; Experimental)
5. W.P. Bloxam, “The Hydrosulphides, Sulphides and Polysulphides ofNH4NaandK,≓Z. Anorg. Chem., 60(2), 113–122 (1908) in German. (Equi Diagram; Experimental)