Arthur F. Buehler. Sufi Heirs of the Prophet: The Indian Naqshbandiyya and the Rise of the Mediating Sufi Shaykh.
Itzchak WEISMANN, The Naqshbandiyya. Ortodoxy and activism in a worldwide Sufi tradition. New York, Routledge, 2007.
Tāj al-Dīn b. Zakariyyā (d. 1050/1640) and His Risāla fī sulūk al-ṭarīqat al-Naqshbandiyya (al-Tājiyya)