Gw mau tau Karya Tulis dari Colin Challen

The Price of Power: Secret Funding of the Tory Party (VISION Investigations) by Colin Challen, 1998, Vision Paperbacks / Satin Publications, ISBN 1-901250-18-0

In Defence of the Party: The Secret State,the Conservative Party and Dirty Tricks by Colin Challen, Mike Hughes 1996, Medium Publishing Co., ISBN 1-872398-01-4