Such evidence is considered as an extension of the record. See Clark v. State, Fla., 256 So.2d 551 (1972); Bennett v. Commonwealth, Ky., 463 S.W.2d 331 (1971); Smith v. Director, Patuxent Institution, Md. App., 280 A.2d 910 (1971); Evans v. State, Ark., 471 S.W.2d 346 (1971); Grass v. State, Me., 263 A.2d 63 (1970); State v. Elledge, 81 N.M. 18, 462 P.2d 152 (1969); Hall v. State, 45 ALa.App. 252, 228 So.2d 863 (1969). We find no theory in Boykin that criminal convictions are built upon a piece of paper that must be inked simultaneously with the plea.