may be google scholar is a good website,any one can tell me some other websites?

Hi there,

If you want to find previous PhD thesis, you may request them from British Library ethos services.
If you are looking for peer-reviewed journals you may access them through online sources, depending on your discipline. For scientific, technical, and medical research I recommend science direct, springerlink etc. You need a password to log-in through your university. Hope this helps. 

Thank you very much.(up)

hi! Not website but a life-site -- your supervisor! :-) :-) :-)
I asked mine; he gave me a few, of which two he said were very good.

love satchi