Ewan W. Anderson; Liam D. Anderson (4 December 2013). An Atlas of Middle Eastern Affairs. Routledge. p. 5. ISBN978-1-136-64862-5., Quote: "To the east, Iran, as a Gulf state, offers a generally accepted limit to the Middle East. However, Afghanistan, also a Muslim state, is then left in isolation. It is not accepted as a part of Central Asia and it is clearly not part of the Indian subcontinent".
Kumar, S. Y. Surendra (December 2015). "China's SAARC membership: The debate"(PDF). International Journal of China Studies. 6 (3): 299–311. Archived(PDF) from the original on 18 July 2020. Retrieved 20 October 2020.
Kumar, S. Y. Surendra (December 2015). "China's SAARC membership: The debate"(PDF). International Journal of China Studies. 6 (3): 299–311. Archived(PDF) from the original on 18 July 2020. Retrieved 20 October 2020.