British Rail Train-Crew Manual - Class 25 Locomotives - Fault Finding Data for Class 25 Locomotives with Vacuum, EQ, and Dual Braking Systems.
Issue Date: Unknown   -   BR 33056/42 Issue 1.

More information can be found here Wikipedia - British Rail Class 25  Wikipedia - British Rail Eastern Region  
More Information Regarding Preserved Class 25 Locomotives can be found on the following websites:  Preserved-Diesels  Caledonian Railway Diesel Group