☰ F. Delitzsch, "Psalm 23," from C. F. Keil and F. Delitzsch, Commentary on the Old Testament, Vol. V (Grand Rapids: Eerdmans, nd).pdf
☰ Dale C. Allison, Jr., "Psalm 23 (22) in Early Christianity. A Suggestion," Irish Biblical Studies 5.3 (July 1983): 132-137. pdf 