African boundaries:

http://books.google.com/books?hl=en&id=A8Du4k0udx4C&pg=PR9&lpg=PR9&dq=African+Boundaries&prev=http://books.google.com/books%3Fq%3DAfrican%2BBoundaries&sig=DOSXKnvobpHsd7JRct31YmBGyzY

International Boundaries: A Geopolitical Atlas

http://books.google.com/books?hl=en&id=E7-menNPxREC&pg=PR7&lpg=PR7&dq=international+boundaries&prev=http://books.google.com/books%3Fq%3Dinternational%2Bboundaries&sig=kAb8nGLz2mU6eyzSDNOyaR_5SW4

Borderbase - your online guide to international borders and tripoints

http://www.nicolette.dk/borderbase