The ESM book doesn't, as you say Mike, relate her advice to GEDCOM structures or even to genealogy software generally. Indeed, she is very specific in saying that her formats, etc., relate to the finished, printed product, and she has said on innumerable occasions that just because it looks like that on her advice for a printed report, doesn't mean it has to be entered like that into your database. She would not, for instance, include "Ancestry" as an author, publisher and repository in a citation - once is enough. However, if you have a good reason for duplication inside a single citation in your database, so be it. The major issues with adapting ESM's approaches to FH are twofold: - the basic structure of GEDCOM sources and citations does not lend itself to degrees of sophistication like "source of a source". Doesn't mean you can't do it - just means you end up with lots of free-format text in arbitrary places. Fine so long as you remember that the free-format text actually should have a format; - the individual items inside (say) the title / description of a source have to be written as a string of text that should have a specific format of items. In other words, the item " title / description" should have sub-items. But, as with the above, in programmatic terms, it's just free-format text and the software can't help you. I usually have templates for various types of sources set up as dummy source records. Inevitably, my templates don't quite fit the latest source.... Some American software allows lots of templates for sources / citations - but I do remember someone who thought deeply about her sources and citations saying once: "Hang on, 36 templates just for books is ridiculous!" Incidentally, John - ESM is *not* universally recognised as the authority on citing sources in the US. Amongst those who regard citing sources formally as important, she pretty much is that authority. But as any blogger who mentions citing sources will testify, a substantial portion of American genealogists regard citing sources as too much like hard work and / or a conspiracy by academia and / or a conspiracy to destroy the worth of great-aunt Mabel's impeccable research of the family back to Adam & Eve. Adrian ​