found: Work cat.: Price, D. Perfoliate pennycress (Thlaspi perfoliatum), 2006?:p .2 (in Britain found mainly in the Cotswold Hills, giving rise to the colloquial name "Cotswold Pennycress")
found: Flora Europaea, digital version accessed online, 16 Apr. 2008(Thlaspi perfoliatum; synonyms T. rotundifolium, T. tinei)
found: USDA-ARS GRIN online database, 16 Apr. 2008(Thlaspi perfoliatum; common names Perfoliate Pennycress, Thoroughwort Pennycress; genus Microthlaspi listed as synonym of Thlaspi)
found: USDA-NRCS Plants Database, accessed online 16 Apr. 2008(Microthlaspi perfoliatum, Claspleaf Pennycress)
found: Integrated Taxonomic Information System, accessed online 16 Apr. 2008(Microthlaspi perfoliatum, syn. Thlaspi perfoliatum, common name Claspleaf Pennycress)