Perhaps you should try some spelling variations:
"advances in chemistry sources" » "advances in chemistry courses", "advances in chemistry surfaces", "advances in chemistry studies"
"Advances in clinical studies" » "Advances in empirical studies"

Try widening your search to All Fields.

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: (("Advances in clinical studies") OR ("advances in chemistry sources")).
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