McMillan, Joe (31 October 2001). "Morgan Steamship Co". House Flags of U.S. Shipping Companies. FOTW: Flags Of The World website. Retrieved 7 August 2008.
miramarshipindex.org.nz
Gleaves (p. 255) reports that El Sol was given to the Ward Line in August 1919, which contradicts the entry in the Dictionary of American Naval Fighting Ships. The ownership information contradicts that recorded in the Miramar Ship Index, a database of historical ship information (See: "El Sol". Miramar Ship Index. R.B.Haworth. Retrieved 7 August 2008..)
"El Sol". Miramar Ship Index. R.B. Haworth. Retrieved 19 August 2008.