getting value property from ABRecordRef - Extract Address Book Address Values Tutorial

I was searching for the way to get value properies from an ABRecordRef Object and I found out it was using ABRecordCopyValue:

NSString *name = (NSString *)ABRecordCopyValue(person

, kABPersonFirstNameProperty);

but the great thing I found was an Amazing Tutorial : 

Tutorial: Extract Address Book Address Values on iPhone OS