I know very little about Afghan history, but I’d like to learn about 19th and 20th centuries in Afghanistan. I’m especially interested in Amanullah Khan and Afghanistan’s relationship with the Soviet Union in the 1920s and 30s.
Life of the Amir Dost Mohammed Khan, of Kabul by Mohan Lal Kashmiri is an interesting book. Can be found here.
Soviet Russia and Asia, 1917-1927: A Study of Soviet Policy towards Turkey, Iran, and Afghanistan by Harish Kapur is available on libgen.