This is the html version of the file https://oka-pu.repo.nii.ac.jp/index.php?action=pages_view_main&active_action=repository_action_common_download&item_id=975&item_no=1&attribute_id=18&file_no=1&page_id=29&block_id=64 . Google automatically generates html versions of documents as we crawl the web.