Böwering, G. (1979). The mystical vision of existence in classical Islam: The Qur'ānic hermeneutics of the Ṣūfī Sahl At-Tustarī (d. 283/896). Walter de Gruyter.
Cita Chicago (17th ed.)Böwering, Gerhard. The Mystical Vision of Existence in Classical Islam: The Qur'ānic Hermeneutics of the Ṣūfī Sahl At-Tustarī (d. 283/896). Berlin ; New York: Walter de Gruyter, 1979.
Cita MLA (9th ed.)Böwering, Gerhard. The Mystical Vision of Existence in Classical Islam: The Qur'ānic Hermeneutics of the Ṣūfī Sahl At-Tustarī (d. 283/896). Walter de Gruyter, 1979.
Atenció: Aquestes cites poden no estar 100% correctes.