1. Finney, Essex E. 1963. The viscoelastic behavior of the potato,Solanum tuberosum, under quasi-static loading. Thesis for the degree of Ph.D., Michigan State University, East Lansing. (unpublished)
2. Humphrey, Elmer. 1950. Steps that can be taken to reduce mechanical damage to potatoes at harvest time. Idaho Agr. Exp. Sta. Bull. 278. 12 p.
3. Lampe, Klaus. 1960. Die Widerstandsfähigkeit von Kartoffelknollen gegen Beschädigungen. Eur. Potato J. 3: 13–29.
4. Larsen, Fenton E. 1962. External and internal (blackspot) mechanical injury of Washington Russet Burbank potoatoes from field to terminal market. Am. Potato J. 39: 249–260.
5. Le Clegg, E. L. 1957. Mean separation by the functional analysis of variance and multiple comparisons. U. S. Dept. of Agr., Agr. Res. Service, Washington. 33 p.