I am looking for books or research papers that compare Pali suttas in different versions of the Pali canon, such as the PTS, Siamese, Burmese and Sinhalese versions. I myself know only some works that compare the Pali canon with the Chinese Agamas or Gandhari texts, but not a comparison among versions of the Pali canon. Would very much appreciate your kind suggestions. Comparison of Pali canon, either part or whole, is of interest. Thank you very much in advance and looking forward to your reply.