Richards, George Henry; Clarke, Andrew (1869). "Report on the Suez Canal". Proceedings of the Royal Geographical Society of London. 14 (3): 259–273. doi:10.2307/1799058. JSTOR1799058.
jstor.org
Richards, George Henry; Clarke, Andrew (1869). "Report on the Suez Canal". Proceedings of the Royal Geographical Society of London. 14 (3): 259–273. doi:10.2307/1799058. JSTOR1799058.