Section 3D. The state purchasing agent shall supervise the state printing and all publications by the commonwealth shall be printed under the agent's direction; provided, that this section shall not apply to topographic maps issued by state departments, to legislative printing or to publications required to be issued by the state secretary under sections 2 to 4, inclusive, or under chapter 90 of the resolves of 1920 or any other special law. All publications by the commonwealth shall be distributed under the direction of the state secretary unless otherwise provided.