Article 165 of the Civil Code, if the authorization for an agency is in written form, the power of attorney shall state the name of the agent, matters of agency, authority and period, and shall be signed by the party. Signed or stamped by the agent.

Article 490: If the parties conclude a contract in the form of a contract, the contract shall be established when both parties sign, seal or fingerprint. Before signing, sealing or fingerprinting, one party has performed its main obligations and the contract is established when the other party accepts it.