Greetings,
I am writing in regards to the German language book "Die Höllenmaschine Im U-Boot," which documents the WWI experiences of Captain Herbert Sauer, a U-Boat commander during WWI.

I am writing to see whether anyone has any biographical information relating to Captain Sauer. I am interested to hear what happened to him following the publication of his book, and during WWII.

I am also trying to determine whether this book is still considered copyrighted under German law, as it was published in 1928, or if it is public domain. I know that German laws state that a published work is copywritten as life plus 70 years, but have no idea when Captain Sauer died, or who I would have to contact to quote or use items from this book if it is still protected. I thought one of the experts here might be able to help me.

Thank you in advance for your time and help.

TF