So it looks like a 9x9 Ken Ken puzzle, with the addition of boxes. The Sudoku I found interesting was called "loco sudoku", where the boxes are not square, but instead oddly shaped:
https://www.pleacher.com/mp/puzzles/mathpuz/moblosu.html
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Bill Rock, Allen TX
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Original Message:
Sent: 03-01-2024 11:51
From: Michael Riley
Subject: Killer Sodoku
I have been enjoying Killer Sodoku in the Saturday edition of the Wall Street Journal for over a year now. I prefer it to plain sudoku.
mgr
Narragansett RI
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Michael Riley
Narragansett, RI
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