H. A. Turner, Mc Innis, M., Angell, R. F., and Weber, D. W.,
“Factors Associated with Dystocia in Beef Heifers”,
The Professional Animal Scientist, vol. 8, no. 3, pp. 43 - 47, 1992.
R. J. Raleigh and Turner, H. A.,
“Fall calving yields a bumper crop of benefits”,
Oregon's Agricultural Progress, no. 16. Oregon Agricultural Experiment Station, 1970.