TY - BOOK AU - Porter,M.W. AU - Spiller,R.C. TI - The Barker index of crystals : a method for the identification of crystalline substances U1 - 548 POR S.1-1 PY - 1951///. CY - Cambridge : PB - W. Heffer & Sons, Ltd., KW - Crystallography N1 - 1 v. : crystals of the Tetragonal, Hexagonal, Trigonal and orthorhombic systems ER -