Blank Sudoku grids

Sometimes you want to work on a Sudoku puzzle which is available only in Kindle format or on a web page and it may be convenient for you to handwrite the digits on a paper.
Feel free to download and print the blank Sudoku grids below (available in different formats):

Pdf file with one A4 format page containing four blank Sudoku grids

Pdf file with one US Letter format page containing four blank Sudoku grids

Pdf file with one A4 format page containing one blank Sudoku grid

Pdf file with one US Letter format page containing one blank Sudoku grid