https://www.no-strings.org/pigs/genetics_web.htm ↗Site en anglais
NOTE: This article was originally prepared for the ACBA guide book in the mid 1980s and revised for the 2013 ACBA Guide Book. It may be saved for personal use but may not be reproduced in any other form or otherwise distributed without the express written consent of the ACBA AND the author! © Peter Herman, 2013