*[Force.com Platform Fundamentals: An Introduction to Custom Application Development in the Cloud](http://www.lulu.com/shop/salesforcecom/forcecom-platform-fundamentals/ebook/product-17381451.html)
*[Object-Oriented Programming with Objective-C](https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/OOP_ObjC/OOP_ObjC.pdf)(PDF)
*[Objective-C Succinctly, Syncfusion](https://www.syncfusion.com/resources/techportal/ebooks/objective-c)(PDF, Kindle) *(Just fill the fields with any values)*
*[Programming With Objective-C](https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/Introduction/Introduction.html)(PDF)
*[Programming With Objective-C](https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/Introduction/Introduction.html)