when not acknowledged, may be made either: (a) By the parties executing it, or either of them; or, (b) By a subscribing witness; or, (c) By other witnesses in cases mentioned in § 33117. SOURCE: CC '1195.
Proof Execution. Proof of the execution of an instrument,
21 GCA § 33114 — under Proof and Acknowledgments of Instruments.
21 GCA § 33114