Template:Fryday, 2005
- Fryday, A.M. 2005 The genus Porpidia in northern and western Europe, with special emphasis on collections from the British Isles. Lichenologist 37(1): 1–35. **[RLL List # 198 / Rec.# 26669] - (Recent Literature on Lichens)** doi:DOI:10.1017/S0024282904014628 (PDF)