Purchase And Sales Agreement
Who Can Sign - For partnerships, only general partners can sign a contract, not a limited partner. For LLC's, a managing member or a hired manager can sign. For corporations, the company's president or chief executive officer is presumed to have the authority to sign. For an organization or association, a board president would have the authority, but may require a vote of the governing board to approve the deal.
Only some places where these treaties and agreements are republished are considered "official" and having a binding version of that agreement. So, even if you find a republished version through Google, that may not mean it is a binding replication of the text. Frequently, they are published officially online through particular websites sponsored by the international organization(s) that created the agreement.