Pre 1940 data validated with the help of:
The Match by Match volumes produced by Tony Brown of Soccerdata
Post 1940 data validated with the help of:
Sunday Chronicle Football Annuals, Playfair Football Annuals & Rothmans Football Annuals
Additional thanks to:
Football League Players' Records 1888-1939 by Michael Joyce
Football League Players' Records 1946-1984 by Barry Hugman
Mr Ted Jones and Mr Clive Richardson
