Heller y Mahmoudi, 1992, p. 421. Heller, Wendy M.; Mahmoudi, Hoda (1992). «Altruism and Extensivity in the Bahá’í Religion». En Oliner, Pearl M.; Oliner, Samuel P.; Baron, Lawrence; Blum, Lawrence A.; Krebs, Dennis L.; Smolenska, M. Zuzanna, eds. Embracing the Other: Philosophical, Psychological, and Historical Perspectives on Altruism (ch. 19, pp. 420–432). New York, NY: New York University Press. doi:10.2307/j.ctt9qg24m.29.
Heller y Mahmoudi, 1992, p. 421. Heller, Wendy M.; Mahmoudi, Hoda (1992). «Altruism and Extensivity in the Bahá’í Religion». En Oliner, Pearl M.; Oliner, Samuel P.; Baron, Lawrence; Blum, Lawrence A.; Krebs, Dennis L.; Smolenska, M. Zuzanna, eds. Embracing the Other: Philosophical, Psychological, and Historical Perspectives on Altruism (ch. 19, pp. 420–432). New York, NY: New York University Press. doi:10.2307/j.ctt9qg24m.29.