OBNB doesn't sell books, but you may be able to find a copy at one of these websites:
Burza nad Lwowem : reportaż z lat Wojennych 1939-1945 we Lwowie ; Kartki z pamie̢tnika by Barbara Me̢karska-Kozłowska. ISBN 0850652456. Published by Polska in 1992. Publication and catalogue information, links to buy online and reader comments.