References
- Dahl , E. and Krog , H. 1973 . Macrolichens of Denmark, Finland, Norway and Sweden Oslo
- Hawksworth , D.L. , Rose , F. and Coppins , B.J. 1973 . “ Changes in the lichen flora of England and Wales attributable to pollution of the air by sulphur dioxide ” . In Air Pollution and Lichens Edited by: Ferry , B.W. , Baddeley , M.S. and Hawksworth , D.L. 330 – 367 . London In
- James , P.W. 1965 . A new check-list of British lichens . Lichenologist , 3 : 95 – 153 .
- James , P.W. 1966 . A new check-list of British lichens: Additions and corrections-1 . Lichenologist , 3 : 242 – 247 .
- Lindsay , W.L. 1856 . A Popular History of British Lichens London
- Poelt , J. 1969 . Bestimmungsschlüssel Europäischer Flechten Lehre
- Seaward , M.R.D. 1970 . The lichen Parmelia incurva (Pers.) Fr. in Yorkshire . Naturalist , : 130 – 130 .
- Seaward , M.R.D. 1971 . A Guide to the Lichenological Collection of Thomas Hebden (1849–1931) Keighley
- Seaward , M.R.D. 1972 . William Johnson's lichen collection . Naturalist , : 13 – 14 .
- Watson , W. 1935 . Notes on lichens, mainly from Orkney, in the herbarium of the Royal Botanic Garden, Edinburgh . Trans, bot. Soc. Edinb. , 31 : 505 – 520 .
- Watson , W. 1939 . Notes on lichens in the herbarium of the Royal Botanic Garden, Edinburgh. II . Trans, bot. Soc. Edinb. , 32 : 502 – 515 .
- Watson , W. 1942 . Notes on lichens in the herbarium of the Royal Botanic Garden, Edinburgh. III . Trans, bot. Soc. Edinb. , 33 : 183 – 208 .
- Watson , W. 1953 . Census Catalogue of British Lichens London