1. Device to aid in selecting and counting seeds;Brown;J. Range Mgmt,1967
2. A semi-automatic seed counter;Brown;J. agric. Engng Res.,1959
3. An electronic seed counter and group number discriminator;Carlow;J. agric. Engng Res.,1960
4. Electronic seed counters;Carlow;J. agric. Engng Res.,1968
5. Counter-planter for grain Sorghum in green-house flats;Carlson;J. Agron.,1960