Any one can help on how to do systematic search for the literature, I have tried all the keywords I have in mind, but nothing works,
???
Please help
Many Thanks

You might need to think a bit laterally, and search on related terms and terms you think are less likely. When I've been stuck I've also gone back to an article that's been on the area I want the lit on, and had a look at the library entry for the article to see what keywords are used. Using the same keywords as the library entry usually brings up some additional material. Also make sure you use a wide range of databases. I find that as long as I have one article, this is a good starting point. Use the same keywords, and chase up references in that one article and you should be on the way.

Many thanks for your valubale advices,
I will try that

Regards