Guess where that figure of 89% came from? All the places mentioned above plus The British Library, National libraries of Scotland, Ireland and Wales etc. etc. I quickly learned how to spot those that relate to folk songs and those that didn't, copied all of those that could have related to folk in some way, checked them alongside their later oral versions and came up with that percentage. A lot of Child's grubbing around but enjoyable most of the time, over a period of 50 years or so.