What's a good book?

[djamel medjahed]

My vote goes to the work of GEORGE H. STOUT and LYLE H. JENSEN :
"X-RAY STRUCTURE DETERMINATION"
 A PRACTICAL GUIDE.
The other book that I have (in french, but I am sure there is a translation in
english is by one the fathers of crystallography : A. GUINIER :
THEORIE ET TECHNIQUE DE LA RADIOCRYSTALLOGRAPHY 
It is very rich in all the mathematical tools used in the field.
Best of luck.