You should probably include the source of the framework yourself manually or much more simply using cocoapods.
Here is the github link to the SDK source: https://github.com/facebook/facebook-ios-sdk
The official cocoapod is named "Facebook-iOS-SDK", if you decide to go that route. I recommend doing this as it is much simpler to install the SDK and update it later on. Cocoapods are very nice for external components in general and will almost certainly save you time and frustration in the long run.