Literature

• Robert, V., Stegehuis, G., Stalpers, J. 2005. The MycoBank engine and related databases. [link]
• Sipman, H. 2007. Lichens. Plants and Lichens of Saba. [link]

Literature references linked to higher taxa

• Sipman, H. 2008. Lichens. Plants & Lichens of St. Eustatius The New York Botanical Garden. [link] (Dirina approximata)