Volcanological map ... (Topographical map of Prince Edward Island. 1:50,000 / 
Langenegger, O.
Verwoerd, W. J.
[Cape Town :  A.A. Balkema, 
1971]
In: Marion and Prince Edward Islands. Report on the South African biological & geological expedition, 1965-1966 ... Edited by E.M. van Zinderen Bakker [and others]
The map is in a pocket at the back of the volume.