1. Survey of LICHEN DETERMINATION KEYS available on INTERNET; regularly updated.

2. CATALOG OF LICHENS IN ROMANIA by Dr. Maria Ciurchea; posted February 2004.

3. UNDER CONSTRUCTION: provisional determination keys for the GRAPHIDALES OF COSTA RICA by H. Sipman; last update 21 July 2005.

4. Key to the lichen genera of Iran by H. Sipman; last update 19 September 2006.

5. Pictures of AEGEAN LICHENS ; last update 3 January 2007.

6. Pictures of SINGAPORE LICHENS ; last update 2 June 2007.

7. Macrolichen keys and Checklist for NEW GUINEA LICHENS, by A. Aptroot; last update 1 Febr. 2010. (pdf-file for downloading)

8. Provisional identification keys for LICHENS FROM REUNION; last update 24 May 2011.

9. Provisional identification key for the lichen genus CLADONIA IN S.E. BRAZIL; last update 24 May 2013.

10. Pictures of PORTO SANTO LICHENS ; last update 14 August 2019.