WEBSTER, F.G.A. Robert
The gemmologists' compendium - 5th rev. ed. - London N.A.G.press Ltd. 1970 - 235 p.
31621
553.8 / WEB
The gemmologists' compendium - 5th rev. ed. - London N.A.G.press Ltd. 1970 - 235 p.
31621
553.8 / WEB