More likely:

It looks like the string you provided — "thmyl-ktab-talm-alsbahh-pdf-llkatb-barth-dyatzyh" — is likely a of an Arabic phrase into Latin letters.

" by and Jürgen Dietze (often referred to in Arabic translations as "Barth/Dietze" or "بارث ديازي"). Why This Book Stands Out

The book is available in multiple languages, including Arabic and English, and can be found on several platforms: Arabic Version : Can be purchased through the Neel wa Furat bookstore English/Digital Versions : Available as an e-book (PDF/EPUB) on Training Sequel : For more advanced learners, the authors also wrote "Swimming: Training,"