Perhaps you should try some spelling variations:
"advances in chemistry specimen" » "advances in chemistry species", "advances in chemistry sediment", "advances in chemistry special"
"advances in chemistry sources" » "advances in chemistry courses", "advances in chemistry surfaces", "advances in chemistry studies"

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

• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"advances in chemistry sources\") OR (\"advances in chemistry specimen\"))".
• Removing quotes may allow a broader search: (( advances in chemistry sources ) OR ( advances in chemistry specimen )).
• Adding a wildcard symbol may retrieve word variants: (("advances in chemistry sources") OR ("advances in chemistry specimen"))*.