Other than books covering the copper and bronze coinage (Peck, Bramah, Freeman etc), there are no specific farthing books that I am aware of. It is a project I am looking into at the moment. The Colin Cooke catalogues are the only other literature that used to have features on varieties etc. Good luck with the project, Colin G. Can the Colin Cooke catalogues still be purchased. I've looked on the Colin Cooke web site but it states 'At present, we have no catalogues available for purchase'.