2005/09/14 tough puzzle from sudoku.com.au

Initial position :

1) Easy eliminations :

h1=8%col, e3=8%row, h2=9%col, a2=1%row, g1=1%row, d9=1%row, h7=1%row, g3=5%col, g5=3%col, c7=3%col, b5=2%cell, h5=4%cell, i1=4%cell, i6=7%block, i4=5%col, b4=1%cell, e6=1%row, e8=9%col, i9=9%row, i8=8%col, i7=2%col, e4=2%col, h6=2%row, h4=6%col, e2=3%col, i3=3%row, e7=7%col, i2=6%col, b6=5%cell, c2=5%cell, d1=5%col, a1=7%block
lead to (for better reading, only remaining possibilities in still empty cells are written) :

2) 67 in R9 are in bg9 so c3=6%col and b3=4%cell . We're now at :

3) Look at 2 in Bb2 : whether it's in c1, in which c5=9%col, or it's in a3, in which d3=9%row : d5=7%cell. From here it's straight to end.

(Details if needed : f2=7%row, d2=4%row, f4=4%row, a4=8%row, c9=8%row, f5=8%row, c5=9%row, f1=9%row, d6=9%row, a3=9%row, f6=6%row, g7=6%row, b9=6%row, g9=7%row, b8=7%row, d8=6%row, a7=4%row, f7=5%row, a9=5%row, g8=4%row, f8=3%row, a6=3%row, d4=3%row, f9=2%row, a8=2%row, d3=2%row, c1=2%row )

See equivalent puzzles : 11-sept, 14-sept, 15-sept, 18-sept, 19-sept, 23-sept, 30-sept.