these are still very weak sources apart from the piece by lloyd which appears to be an undergraduate project as discussed above what you've added is the abstract of a non peer reviewed paper presented at the annual meeting of an association and a lecture handout that appears to have been put online by its author none of your three sources support the sentence the roman constitution had three main powers as i've already discussed above lloyd describes polybius as seeing the roman constitution this way not montesquieu so i'm going to remove this sentence again the rest of your additions can remain i think and i will also format the references you added talk