Fantastic Fiction,[2] list Adam Hardy as one of Harknett's pseudonyms, in fact a nom de plume of Kenneth Bulmer.
This is an error [3] resulting from incorrect copyright information printed in one of the Edge westerns.
Harknett wrote a number of fiction series including: Harknett's authorship of the Edge, Steele, Jubal Cade and Apache series, as well as his novelisation of the film A Fistful of Dollars (under the pseudonym Frank Chandler, Tandem Books [1972]) earned him the description of 'One of the authors of "Blood and Soil" Western fiction'.
[4] Harknett's westerns have been identified as an influence by authors including Robert J. Randisi[5] and Peter Brandvold.
Under that name Harknett wrote three series of Western books: Edge, which his US publisher would brand "The Most Violent Westerns in Print", Adam Steele (this character and Edge appeared together in three books) and The Undertaker.