Mokoena, M., and M. Oberholzer. “Analyzing Biographical Differences on Employees’ Perception of Safety Control Measures With Special Emphasis on the Cost Thereof at a Colliery”. Journal of Economics and Behavioral Studies, Vol. 8, no. 6(J), Jan. 2017, pp. 68-81, doi:10.22610/jebs.v8i6(J).1484.