1. Banki, M. The relationship between the mental environment of workers and the incidence of injuries. thesis presented to the University of Missouri. Columbia, MO. in partial fulfilment of the requirements for the degree of Doctor of Philosophy,
2. Hinze, J. The effect of middle management on safety in construction. thesis presented to Stanford University. in partial fulfilment of the requirements for the degree of Doctor of Philosophy, Dept. of Civil Engineering.
3. Safety: Productivity and Job Pressures