Black Sabbath's Paranoid tab

I have collected this intro through experience and tutoring with friends, I find this 
fairly simple. It's a great song and it sound awesome once you start to play it!

e:--------------------------------------|
B:--------------------------------------|
G:---9--9--9----------7--9--------7--9--|
D:---9--9--9---7--9---------7--9--------|  x4 (play with heavy distortion for a greater sound)
A:---7--7--7----------------------------|
E:--------------------------------------|

The song goes on to continue with the guitar and bass playing the same riff.
This was my first tab and I hope this helped.