Template:Ohlsson, 1973a
- Ohlsson, K.E. 1974 [ '1973' ]. A revision of the lichen genus Sphaerophorus. [A thesis submitted to Michigan State University in partial fulfillment of the requirements for the degree of Ph. D. Department of Botany and Plant Pathology 1973.]: 1–286. (unpublished) MycoBank ProQuest