[1]    M.B. Jr. Colket. The Royal Ancestry of the Ludlows. The American Genealogist, 15:129–143, 1939.

[2]    H.F. Seversmith. The ancestry of Roger Ludlow: with connections to the peerages and Royal families of England, Ireland, Scotland and France. The American Society of Genealogists, Chevy Chase, Maryland, 1958.

[3]    N. McWhirter and R. McWhirter, editors. The Guinness Book of Records. Guinness Superlatives Ltd., Enfield, Middlesex, UK., 1971.