Secondary sources should be used sparingly. Try to locate the original source of information cited in the secondary work if it is possible. If you read an article or book which cites some information that you want to cite, always refer to the source where you found the information, not the original source.
In your footnote, cite the original source, as well as the source where you located in the information. In your bibliography, cite only the source that you consulted.
Bibliography:
Lienhard, Joseph T., editor. Exodus, Leviticus, Numbers, Deuteronomy. Ancient Christian Commentary. Downers Grove, IL: InterVarsity Press, 2001.
Footnote:
1. Augustine, “Tractate on the Gospel of John 20.2,” in Fathers of the Church: A New Translation (Washington, DC: Catholic University of America Press, 1947), 79:164, quoted in Joseph T. Lienhard, ed., Exodus, Leviticus, Numbers, Deuteronomy, Ancient Christian Commentary (Downers Grove, IL: InterVarsity Press, 2001), 104.
