Template:Aptroot, 1991a
- Aptroot, A. 1991. A Monograph of the Pyrenulaceae (Excluding Anthracothecium and Pyrenula) and the Requiennellaceae, with Notes on the Pleomassariaceae, the Trypetheliaceae and Mycomicrothelia (Lichenized and Non-lichenized Ascomycetes). Bibliotheca Lichenologica 44: 1–178. RLL List # / Rec.# 766 – Recent Literature on Lichens Schweizerbart