This series of books by Hermann Hesse was published by Bertelsmann Gütersloh as edition for book clubs – probably in the late 1970s. The multiline typeface is Blackline, designed by Wolf Magin in 1969 and released by H. Berthold AG in 1976.
You’re welcome. I was sure you must have noticed these while looking for the Hesse covers, but when they didn’t appear with the others, I went ahead. It’s a pity that there are no better images available. We should do such ping-pong chain posts here more often!