Unknown Author
F. Foglierini
Jadwiga Pawłowska
Stephen S Howe
United States. Bureau of Mines.
J. G. Blockley
Richard Davy
D. F. Sangster
S. F. Bugg
Sayamadas Banerjee
James T. Fyles
Allen Van Heyl
M. Deb
John Patrick Albers
Cynthia Margaret Saunders
Edwin Gilpin
Geological Survey of Canada. Section of Mines
Charles Henry Smyth