Complex stuf Physical Application

[kthouz]

CAn some body tell me some physical applications of the "residuum theorem" and the "isolated singular point"

[pallidin]

Would you elaborate, and give a reference to your question, so that we can help.

[kthouz]

Clearly i need to know more about the applications of functions of complex variables. Especially, the physical meaning(application) of "isolated singular point","a residue of a complex function"," a meromorphic function". If any one know a link on the complex analysis and its applications can tell me. Or a book, i will try to download it. Thank you!