Are there any additional places where actors can locate Talent Agents or Casting Directors?

You can find listings online for Talent  Agents at   agentassociation.com and you  can familiarize  yourself  with  some of the  major Casting Directors  by visiting   hollywoodactorsassociation.com.  Also,  you  should visit  the Samuel French  Bookstore where  you can find many  resourceful  books and  directories such as  Talent Agent  Directories  which can  provide  you with specific  information for  each such as the type of actors they are  accepting submissions from.  Samuel French has a website  but they do not appear to sell many of the directories they have available and updated on a bi-weekly basis that they offer at their physical stores in Los Angeles.