The Supreme Court of the State of California has construed the law in question here, the California Retail Sales Tax, St.Cal.1933, p. 2599, as a tax upon *250the seller and not upon the buyer. Western Lithograph Co. v. State Board of Equalization, 11 Cal.2d 156, 78 P.2d 731, 117 A.L.R. 838. This interpretation is binding on the United States Courts. Erie Railway Co. v. Tompkins, 304 U.S. 64, 58 S.Ct. 817, 82 L.Ed. 1188, 114 A.L.R. 1487. The facts seem to bring the case within the reasoning of James v. Dravo Contracting Co., 302 U.S. 134, 58 S.Ct. 208, 82 L.Ed. 155, 114 A.L.R. 318, and I am compelled to disagree with the learned referee in bankruptcy.

The amendment to the act of June 30, 1939, Section 5 (f), St.Cal.1939, p. 2173, could not operate to invalidate the obligations which had already become fixed. Estate of Stanford, 126 Cal. 112, 54 P. 259, 58 P. 462, 45 L.R.A. 788.

The petition for review is granted, and order of the referee is reversed.