[2021-09-05]. ISBN 978-1-136-80339-0. (原始内容存档于2022-06-15) (英语). Allan, Nigel. Defining Place and People in Afghanistan. Post-Soviet Geography and Economics
Heinrich Karl. 新国际百科全书 (第1版). 纽约: Dodd, Mead. 1905. Martin Lengwiler, Nigel Penn, Patrick Harries. Science, Africa and Europe: Processing Information and Creating