On Archive.org. Disregard its listing as Orthodox, this is the Hicksite version. The “Book of Discipline” is more commonly known as “Faith and Practice” these days and is the most official document of Friends beliefs for the region & group it serves. I love the handwritten note on the inside back cover, which is a copied passage on Friends from Rufus Jones. Via Chris Pifer on a Facebook thread.
Archive.org has a lot of Quaker material, some originally scanned by Google, so it should be there too.
