The Traditional Ballad Index lists these ballads for the Child and Laws numbers Susan mentions:

Child 7         Roud 23         Earl Brand
Laws M27       Roud 321       The Bold Soldier

Child 43       Roud 34         The Broomfield Hill
Laws K27       Roud 181       The Maid on the Shore

Child 53       Roud 40         Young Beichan
Laws O26       Roud 8124       The Turkish Lady

Child 112       Roud 11         The Baffled Knight
Laws N24       Roud 674       Katie Morey

Child 283       Roud 2640       The Crafty Farmer
=Laws L1         Roud 2640       The Crafty Farmer

Child 295       Roud 180       The Brown Girl
Laws P9         Roud 180       A Rich Irish Lady

The first four pairs are categorised as different but related songs referring to each other.