Oxford Dictionary of National Biography
W. A. Speck, Harley, Robert, first earl of Oxford and Mortimer (16611724), first published 2004; online edn, Oct 2007, 8901 words, with portrait illustration
http://dx.doi.org/10.1093/ref:odnb/12344
> View Robert Harley complete biography [Oxford DNB subscription required; no subscription?]
