Dickson, T. A. <br/><br/>
Studies in Crataegus L. (Rosaceae : Maloidea) XII. Degree and pattern o f phenotypic variation in Crataegus sect Crus-galli in Ontario 

<br/><br/> Sobretiro de : Systematic botany 10 (3: 322-37, 1985. 
<br/><br/><label>LCCN: </label>67369 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Tejocote--Genética.