TY  - BOOK
AU  - Dickson, T. A.
TI  - Studies in Crataegus L. (Rosaceae : Maloidea) XII. Degree and pattern o f phenotypic variation in Crataegus sect Crus-galli in Ontario
KW  - Tejocote
KW  - Genética
N1  - Sobretiro de : Systematic botany 10 (3: 322-37, 1985
ER  -