The version given above appears to be closest to the version published by Scott in his Minstrelsy of the Scottish Border. Unfortunately Child included this relatively late (18thc) ballad in with a ballad called Earl Brand (Child 7) which tells more or less the same story. Nowadays we would treat them as 2 separate songs as they have no text in common except for the motif of the girl holding the horse which also occurs in some more recent ballads like The Bold Dragoon.

It has been reprinted in many ballad anthologies so it shouldn't be difficult to get hold of a copy. Even copies of Child's first volume which gives about 8 variants is relatively easy to get hold of and very cheap. Try Amazon.