Gerard McAtasney is a Belfast author and Historian. He has written many historical books . All of his Leitrim books are available in the Leitrim County Library. "Leitrim and the Croppies" I think is out of Print. If you Google Gerard McAtasney you will find information on the material he has written.
Contact Drumlin Publications in Manorhamilton Co Leitrim
http://www.drumlinpublications.com/index.html