1. Taxonomic studies in reindeer lichens (Cladonia, subgenus Cladina);Ahti T.;Annales Botanici Societatis Zoologicae Botanicae Fennicae 'Vanamo',1961
2. The Cladonia gorganina group and C. gigantea in East Africa;Ahti T.;Lichenologist,1977
3. Cladoniaceae;Ahti T.;Flora Neotropica,2000
4. Lichen Flora of the Greater Sonoran Desert Region: I. Lichens Unlimited;Ahti T.,2002
5. Studies on Cryptogams in Southern Chile;Ahti T.,1984