Kärnefelt, EI/ Thell, A 2000: On the systematic position of the genus Cetrariella (Parmeliaceae: Ascomycotina) indicated by ITS rDNA data. - Bibliotheca Lichenologica75: 27-32. [RLL Suppl.] Abstract: Cetrariella delisei and C. fastigiata appear as not very closely related species, based on sequences from ITS region.