Need References on Objective-C

[Sean Jiam]

Hello,

	I am going to have a class presentation on Objective-C.  I have
read the book "Object Oriented Programming" by Brad Cox, but I still have
some doubts about the language implementation. 

	If anyone has any references on the language, I would really
appreciate if you can send them to me through E-mail at:
        	seanjiam at umn-cs.cs.umn.edu.arpa.

	Thanks a lot!

					Sean Jiam.