4[6]Hermann Rüter, Ludwigshafen, et al. Production of alpha -calcium sulphate hemihtdrate [ P]. US 3410655, 1968 - 11 -12.
5[7]Gerhard Bayer, Ludwigshafen Rheing? nheim, et al. Plaster carts[P]. US 3913571,1975 - 10- 21.
6[8]Marinkovic S., Kostic- Pulek A., et al. Products of hydrothermal treatment of selenite in potassium chloride solutions [J]. J. Them. Anal. Calor., 1999,57(2),559-567.
7[9]Imahashi Masayuki, et al. Transformations of gypsum to calcium sulfate hemihydrate and hemihydrate to gypsum in NaCl solutions[J]. Bull. Chem. Soc. Jpn., 1994,67(7), 1961-1964.
