| Lichen-Forming and Lichenicolous Fungi of Fennoscand R Santesson, R Moberg, A Nordin, T Tønsberg, O Vitikainen Lichen-Forming and Lichenicolous Fungi of Fennoscand, 2004 | 1020 | 2004 |
| The sorediate and isidiate, corticolous, crustose lichens in Norway T Tønsberg Sommerfeltia 14 (1), 1-336, 1992 | 471 | 1992 |
| Lavflora: norske busk-og bladlav H Krog, H Østhagen, T Tønsberg, H Østhagen, T Tønsberg Universitetsforl., 1980 | 287 | 1980 |
| Santesson’s checklist of Fennoscandian lichen-forming and lichenicolous fungi A Nordin, R Moberg, T Tønsberg, O Vitikainen, Å Dalsätt, M Myrdal, ... Ver. April 29, 2011, 2011 | 253 | 2011 |
| Phylogeography of Cavernularia hultenii: evidence of slow genetic drift in a widely disjunct lichen C Printzen, S Ekman, T Tønsberg Molecular Ecology 12 (6), 1473-1486, 2003 | 148 | 2003 |
| The threatened macrolichens of Norway-1995 T Tønsberg, V Gauslaa, R Haugan, H Holien, E Timdal Sommerfeltia 23 (1), 1-1, 1996 | 135 | 1996 |
| Lichens and lichenicolous fungi of the Klondike Gold Rush National Historic Park, Alaska, in a global biodiversity context T Spribille, S Pérez-Ortega, T Tønsberg, D Schirokauer The Bryologist 113 (3), 439-515, 2010 | 131 | 2010 |
| Most species of Lepraria and Leproloma form a monophyletic group closely related to Stereocaulon S Ekman, T Tønsberg Mycological Research 106 (11), 1262-1276, 2002 | 121 | 2002 |
| Boreal regnskog i Norge–habitatet for trøndelagselementets lavarter H Holien, T Tønsberg Blyttia 54 (4), 157-177, 1996 | 93 | 1996 |
| Lichens and associated fungi from Glacier Bay National Park, Alaska T Spribille, AM Fryday, S Pérez-Ortega, M Svensson, T Tønsberg, ... The Lichenologist 52 (2), 61-181, 2020 | 88 | 2020 |
| The lichen flora of Svalbard D Øvstedal, T Tønsberg, A Elvebakk Sommerfeltia 33 (1), 3-393, 2009 | 86 | 2009 |
| Molecular systematics of the wood-inhabiting, lichen-forming genus Xylographa (Baeomycetales, Ostropomycetidae) with eight new species T Spribille, P Resl, T Ahti, S Pérez-Ortega, T Tønsberg, H Mayrhofer, ... Acta Universitatis Upsaliensis. Symbolae botanicae Upsalienses: Arbeten fran …, 2014 | 83 | 2014 |
| Considerations and consequences of allowing DNA sequence data as types of fungal taxa JC Zamora, M Svensson, R Kirschner, I Olariaga, S Ryman, LA Parra, ... IMA fungus 9, 167-175, 2018 | 77 | 2018 |
| The lichen genus Rinodina (Physciaceae, Caliciales) in north-eastern Asia JW Sheard, AK Ezhkin, IA Galanina, D Himelbrant, E Kuznetsova, ... The Lichenologist 49 (6), 617-672, 2017 | 74 | 2017 |
| Phycotype pairs in Nephroma, Peltigera and Lobaria in Norway T Tønsberg, J Holtan–Hartwig Nordic Journal of Botany 3 (6), 681-688, 1983 | 64 | 1983 |
| The lichen genus Biatora in northwestern North America C Printzen, T Tønsberg Bryologist, 692-713, 1999 | 60 | 1999 |
| Contributions to an epiphytic lichen flora of northwest North America: I. Eight new species from British Columbia inland rain forests T Spribille, CR Björk, S Ekman, JA Elix, T Goward, C Printzen, T Tønsberg, ... The Bryologist 112 (1), 109-137, 2009 | 59 | 2009 |
| Lecanora thysanophora, a common leprose lichen in eastern North America RC Harris, IM Brodo, T Tønsberg Bryologist, 790-793, 2000 | 54 | 2000 |
| Convergent evolution of a symbiotic duet: The case of the lichen genus Polychidium (Peltigerales, Ascomycota) L Muggia, P Nelson, T Wheeler, LS Yakovchenko, T Tønsberg, T Spribille American Journal of Botany 98 (10), 1647-1656, 2011 | 53 | 2011 |
| Sticta oroborealis sp. nov., and Other Pacific North American Lichens Forming Dendriscocauloid Cyanotypes T Tønsberg, T Goward The Bryologist 104 (1), 12-23, 2001 | 51 | 2001 |
