Tax Law, § 4(d) of § 1340(c); Codes and Ordinances of the City of Yonkers, § 92-101(d)
Income from and deductions connected with the rental of real property and gain and loss from the sale, exchange or other disposition of real property are not subject to allocation under section 262.2 of this Part, but are considered as entirely derived from or connected with the place in which such real property is located.
N.Y. Comp. Codes R. & Regs. Tit. 20 § 262.3