Reddit reviews Learning Objective-C 2.0: A Hands-On Guide to Objective-C for Mac and iOS Developers

Swift:

• The Swift programming Language https://swift.org/documentation/TheSwiftProgrammingLanguage(Swift3.1).epub
  
• Swift Programming: The Big Nerd Ranch Guide https://www.bignerdranch.com/books/swift-programming/
  
• iOS Programming: The Big Nerd Ranch Guide https://www.bignerdranch.com/books/ios-programming/
  
• Advanced Swift https://www.objc.io/books/advanced-swift/
  
• Functional Swift https://www.objc.io/books/functional-swift/
  
  
  Objective-C
  
  
• Objective-C Programming: The Big Nerd Ranch Guide https://www.bignerdranch.com/books/objective-c-programming/
  
• Learning Objective-C 2.0 https://www.amazon.com/Learning-Objective-C-2-0-Hands-Developers/dp/0321711386
  
• Effective Objective-C 2.0 Effective Objective-C 2.0: 52 Specific Ways to Improve ... - Amazon.com
  
• Programming in Objective-C https://www.amazon.com/Programming-Objective-C-6th-Developers-Library/dp/0321967607
  
• Programming with Objective-C https://developer.apple.com/library/prerelease/content/documentation/Cocoa/Conceptual/ProgrammingWithObjectiveC/Introduction/Introduction.html#//apple_ref/doc/uid/TP40011210