another few background books ..
Handbook of Aircraft Performance
John Grover BSP Professional Books ISBN 0-632-02304-X
Flight Operations
Charles Owens Granada ISBN 0-246-11643-9
Flight Planning
G D P Worthington Pitman ISBN 273-42424-6
and for an ancient one in the post war era
The Performance of Civil Aircraft
F B Baker Pitman
.. the things one finds in the dusty corners of the bookshelf ...