Found it!

You never know where a fragment could hide. When you search in a manuscript or printed book, a fragment is usually placed as a pastedown or a flyleaf or as a reinforce outside a quire. When it is used as a reinforce on the spine, it is much more difficult to detect its presence, since it is usually glued and hidden behind the cover… unless the binding is somehow broken. That’s when a fragment-searcher gets lucky: here there are some very small fragments from a 14th century French Breviary. Judging from the dimensions of the script and initials, the book was a portable one. The text we can see is not enough to determine the liturgical use of the original Breviary, but we can read the beginning of the first antiphon for Lauds, “Emissiones tuae”, used for the common of the virgins. (Found in Paris, BnF, fonds Latin).