Gary. Bowersox

Emeralds of the Panjshir Valley, Afghanistan

L. Snee, R. Seal, E. Foord, 1991 .

A Status Report on Gemstones from Afghanistan

Gary. Bowersox, 1985 .

Ruby and Sapphire from Jegdalek, Afghanistan

J. Shigley, Christopher P. Smith, E. Foord, 2000 .