Perhaps you should try some spelling variations:
"factor system / great britain" » "factory system / great britain", "reactor system / great britain", "actor systems / great britain"
"vector system / great britain" » "vector systems / great britain"

Try widening your search to All Fields.

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• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"factor system / great britain\") OR (\"vector system / great britain\"))".
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