According to Okugaki (postscript), Kamitsumaki and Shimotsumaki are the books of ONAKATOMI no Sadayo and Nakatsumaki is the book of FUJIWARA no Michimasa in the basic book of popular edition.
奥書によれば、祖本は上・下巻が大中臣定世本、中巻が藤原通雅本である。