Perhaps you should try some spelling variations:
"China 2020 series" » "China 2021 series", "China 27000 series", "China 9000 series"
"China 7000 series" » "China 27000 series", "China 9000 series", "China 6000 series"
china 2020 » china 2021, china 20
china 7000 » china 1000, china 1200, china 1600

Try widening your search to All Fields.

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: "((\"China 2020 series\") OR (\"China 7000 series\"))".
• Removing quotes may allow a broader search: (( China 2020 series ) OR ( China 7000 series )).
• Adding a wildcard symbol may retrieve word variants: (("China 2020 series") OR ("China 7000 series"))*.