The following articles about Cocoa are published in MacFreak Magazine (unfortunately no longer published). These articles are written in Dutch.
MyGraphView:NSView
Sample code for article: “MyGraphView:NSView” MacFreak Magazine 1 april/mei 2005
MyGraphView.zip | MyGraphView.pdf
Cocoa Bindings
Sample code for article: “Een introductie: Cocoa Bindings” MacFreak Magazine 0 januari/februari 2005
MacFreak00.zip | CocoaBindings.pdf