Perhaps you should try some spelling variations:
"advanced in chemistry sources" » "advanced in chemistry courses", "advanced in chemistry surfaces", "advanced in chemistry studies"
"advanced in chemistry series" » "advanced in chemistry species", "advanced in chemistry studies", "advanced in chemistry erich"

Try widening your search to All Fields.

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