APA (7e ed.) Bronvermelding

Symons, I. F., Clayton, C. R. I., & Darley, P. (1989). Earth pressures against an experimental retaining wall backfilled with heavy clay. Ground Engineering Division, Sturctures Group, Transport and Road Research Laboratory.

Chicago (17e ed.) Bronvermelding

Symons, I. F., C. R. I. Clayton, en P. Darley. Earth Pressures Against an Experimental Retaining Wall Backfilled with Heavy Clay. Crowthorne, Berkshire: Ground Engineering Division, Sturctures Group, Transport and Road Research Laboratory, 1989.

MLA (9e ed.) Bronvermelding

Symons, I. F., et al. Earth Pressures Against an Experimental Retaining Wall Backfilled with Heavy Clay. Ground Engineering Division, Sturctures Group, Transport and Road Research Laboratory, 1989.