Anti-Quads 3

Normal Sudoku rules apply, place the digits 1-9 in each row, column, and box. Quadruples: Digits in a Quadruple white circle must be placed at least once in the four cells touching that circle. Digits that appear twice in white circles must be placed twice in the cells touching that circle. Anti-Quadruples: Digits in the PINK circle cannot appear in one of the four surrounding cells. Anti-Knight: Cells that are a Knight's move apart (in chess) may not contain the same digit.