I have access to ancestry library, which helps me find some things FamSch doesn't have (until I add info to FS, when - miraculously - the sources suddenly appear).
I have no idea how to translate an image on the library to an actual citation, though.
You need to be cautious, though, of the transcriptions on FS, as they aren't always reflective of the actual documents. The Guest=Thompson marriage is an example. FS now has that, but indexed as having been on the 5th June 1925, instead of the 7th June - all because the transcriber saw the crossbar of the t as being the upper bar of a 5.
Thing is, they didn't even apply for the license until the 6th, so could not have legally married prior to that date. (And the image I used is the full page, not a small card notation, as the FS source appears to be. (I can save it and upload it to NOT Wikitree, if you'd like to see it.))