other versions of this surname
links
- https://en.wikipedia.org/wiki/Plessis
- https://www.stirnet.com/genie/data/british/pp/plessetis1.php (membership required to view without interruption)
- https://www.stirnet.com/genie/data/continent/qrstu/szvar01.php#link2 (membership required to view without interruption; surname shown as "de Plessis" but should be "du Plessis")