Respondent's motion to strike the stipulations and exhibits containing such extrinsic evidence is denied. In our opinion the cases cited by respondent on this point (Park Sherman Co. v. United States, 29 T.C. 175; Braden v. War Contracts Price Adjustment Board; 11 T.C.71; and Calif. Eastern Line, Inc. v. Maritime Commission, supra) are irrelevant to its argument.