Hello!
Two new volumes have been published in the series. Links and covers below.
Next one (vol. 4): Betasom: Italian Submarines in the Atlantic 1940-1945 - scheduled for release in 2023!
https://www.amazon.com/dp/B09GPYLYXC
https://www.amazon.com/dp/B09ZV5QS3P
Regards,
Marek