Paphiopedilum hybrids:  their parents and progeny as registered from 1856, including cypripediums andphragmipediums 

 - 2nd edition 
 - Wynnewood, Penn.:  Penn Valley Orchids,  1994. 
 - 619 pages ;  29 cm. 
<br/><br/> Second edition by William W. Wilson 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Paphiopedilum--Varieties.