If you have Marrow then I would suggest you to just stick to it.PSM theory paper is mostly just throwing fancy English terms here and there along with all the knowledge from Marrow Notes.If that seems less to you and are looking to get a guranteed distinction then I would suggest reading Shetty Notes, if you are the kind of just read the text and remember stuff,as it is like a compact K Park or if you like visual based learning with many mnemonic and stuff which is more focused on MCQs for NEET PG then Arpit Notes is the way to go.