Infrared and Raman spectra of magnesium ammonium phosphate hexahydrate (struvite) and its isomorphous analogues. IV. FTIR spectra of protiated and partially deuterated nickel ammonium phosphate hexahydrate and nickel potassium phosphate hexahydrate, - A. Cahil, M. Najdoski, V. Stefov (My University, 2007)