1. Andelic, M., Janjatovic, V., Borojevic, S.: Number and size of stomata in different wheat genotypes. - Savr. Poljopr.18: 803–807, 1970. (Plant Breeding Abst.43: 3462.)
2. Bliss, C. I., James, A. T.: Fitting the rectangular hyperbola. - Biometrics22: 573–602, 1966.
3. Ceulemans, R.: [Comparative laboratory studies of gas exchange characteristics of different poplar clones and the ecological passport as a production-performance index.] In Flem. - Ph. D. Thesis, Universitaire Instelling, Antwerpen 1980.
4. Ceulemans, R., Impens, I., Hebrant, F., Moermans, R.: Evaluation of field productivity for several poplar clones based on their gas exchange variables determined under laboratory conditions. - Photosynthetica14: 355–362, 1980.
5. Cole, D. F., Dobrenz, A. K.: Stomata density of alfalfa (Medicago sativa L.). - Crop Sci.10: 61–63, 1970.