Sources-Curious Myths of the Middle Ages

Curious Myths of The Middle Ages Vol 2 (1882) by Rev Sabine Baring-Gould

This retells the Melusina myth and is followed by a bibliography of early literary works and speculation on the relationship between the Melusina myth and other legends, myths and folktales including mermaids, banshees and ancient gods and goddesses. Here are a few examples (not comprehensive) of where versions of it can be sourced, I have tried to link directly to the relevant web page on a site where possible.

Online Books-Full electronic copies are available for free online. Here is an Internet Archive example and a Google books one

Online Booksellers-For example Amazon and Abe Books

Library

Book shops-(you may have to order), you could try finding an independent local bookshop in your area