Groenkloof Brick, Tile and Pottery Factory Ltd., Pretoria
Magista Slate Quarries, Ltd.
Vianini Ferro - Concrete Pipes (Brits.)
Imperial Chemical Industries
Miscellaneous
Miscellaneous
Publications & articles
Publications & articles
Tony Fitzgerald Lecture, Queensland, Australia
Tony Fitzgerald Lecture, Queensland, Australia
Rock Bursts
Low Grade Ore
Support of Workings