Necesito recuperar la lista deContacts eniOS.

Aquí está mi código que no funciona.

NSMutableArray *myContacts = [[NSMutableArray alloc]init];

    CFErrorRef error = NULL;
    ABAddressBookRef addressBook = ABAddressBookCreateWithOptions(NULL, NULL);
    if (addressBook!=nil)
    {
        NSArray *allContacts = (__bridge_transfer NSArray*)ABAddressBookCopyArrayOfAllPeople(addressBook);

        NSUInteger i = 0;
        for (i = 0; i<[allContacts count]; i++)
        {
            Person *person = [[Person alloc] init];
            ABRecordRef contactPerson = (__bridge ABRecordRef)allContacts[i];
            NSString *firstName = (__bridge_transfer NSString*)ABRecordCopyValue(contactPerson, kABPersonFirstNameProperty);

            person.firstName = firstName;
            [myContacts addObject:person];
        }
        CFRelease(addressBook);

    }
    else
    {
        NSLog(@"Error");

    }

¿Cómo puedo obtener la lista deContacts?