This book tells a story that no one knew existed.

On the backs of photo postcards, sent from Europe to the United States and Argentina during the first half of the 20th century, members of the Greensweig and Moncarz families share the small details of their lives.

These words, written in Yiddish, Hebrew, Spanish and English, were hidden in picture frames until 2012, when they were found and translated. The story the postcards tell is abbreviated, incomplete - and, in many cases, hardly a story at all.

Despite this, these found words from the past are important and interesting, if for no other reason than they are, as their writers say, "for a memory".