R. G. Heard

A Pre-impoundment Survey of the Helminth and Copepod Parasites of Micropterus spp. of Beaver Reservoir in Northwest Arkansas

D. A. Becker, P. D. Holmes, R. G. Heard, 1966 .

The stratigraphy of the Lower Beaufort Group in an area north of Laingsburg, South Africa

B. Rubidge, J. Kitching, J. Loock, 1994 .