Robert H. Richards and Charles E. Locke, assisted by John L. Bray.
RICHARDS, ROBERT HALLOWELL. A text book of ore dressing, 2d ed., rev.
RICHARDS, ROBERT HALLOWELL. A text book of ore dressing, by Robert H. Richards and Charles E. Locke, assisted by John L. Bray. 2d ed., rev. © 29Jun25, A855761. R98264, 5Aug52, Old Colony Trust Co. (E of C. E. Locke)
Old Colony Trust Co.|E of C. E. Locke