Theme: Repeated Groups
Author/Opus: This is the 307th puzzle from Thomas Snyder, aka Dr. Sudoku.
Rules: Standard Sudoku rules.
Answer String: Enter the 1st row from left to right, followed by a comma, followed by the 8th column from top to bottom.
Time Standards (highlight to view): Grandmaster = 1:45, Master = 3:00, Expert = 6:00