Brassica rapa L. | Plants of the World Online | Kew Science
Turnip (Brassica rapa L. subsp. Rapa) — UIC Heritage Garden
Brassica rapa - NordGen
Brassica rapa subsp. oleifera - Wikispecies
Brassica rapa | TRAMIL
Brassica rapa (Chinensis Group) (Bok Choy, Chinese White Cabbage, Field Mustard, Mustard Cabbage, Pak Choi) | North Carolina Extension Gardener Plant Toolbox