Engel Jr., Mylan (2011). "Review of Practical Ethics, 3rd Edition by Peter Singer". The American Journal of Bioethics. 11 (12): 73–75. doi:10.1080/15265161.2011.626728. S2CID57037141.
Engel Jr., Mylan (2011). "Review of Practical Ethics, 3rd Edition by Peter Singer". The American Journal of Bioethics. 11 (12): 73–75. doi:10.1080/15265161.2011.626728. S2CID57037141.