Folio - a book (or manuscript) consisting of large sheets of paper folded in the center for making two leaves or 4 internet pages; "the primary folio of Shakespeare's performs" This area needs extra citations for verification. Remember to help boost this text by introducing citations to reliable sources. Unsourced https://davidhoffmeister.com/david-hoffmeister-the-message/metaphysics-of-a-course-in-miracles/