He is the author of The Unbroken Chain, which traces the great Katzenellenbogen family. While not a member of the Karelitz family, he researched it in 1980's as part of a larger work he is producing on the Epstein family, within which the Karelitz family falls. His contributions form an invaluable bridge between the generations of the original family album and those of today. He contributed to the content of this website.