Weathers, R. C. and Hunt, M. L., et el. (1997) Effects of Horizontal Vibration on Hopper Flows of Granular Material; ISBN 0784402515; Mechanics of deformation and flow of particulate materials : proceedings of a symposium, Evanston, Illinois, June 29-July 2, 1997; 349-360
Wassgren, Carl R. and Hunt, Melany L., et el. (1997) Effects of vertical vibration on hopper flows of granular material; ISBN 0784402515; Mechanics of deformation and flow of particulate materials : proceedings of a symposium, Evanston, Illinois, June 29-July 2, 1997; 335-348
Wassgren, C. R. and Brennen, C. E., et el. (1995) Granular Flow in a Vertically Vibrating Hopper; ISBN 0784400830; ASCE Engineering Mechanics Conference (10th : 1995 : University of Colorado, Boulder); 1111-1114
Brennen, C. E. and Ghosh, S., et el. (1993) Vertical oscillation of a bed of granular material; ISBN 905410323X; Powders & grains 93 : proceedings of the Second International Conference on Micromechanics of Granular Media, Birmingham, UK, 12-16 July 1993; 247-252
