Perhaps you should try some spelling variations:
tu sach » thu sach, su sach, te sach
lang xa » lang ha, dang xay, lang van
qua cac » cua cac
thuc va » thuc vat, thuc dan, thuc day
dao dai » dat dai, dao dan, tao dai
cua tre » cua te, cuu tre, cua triet
y lang » o lang, _ lang, tay lang
tuc va » truc va, duc va, thuc vat

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y lang xa hoi. hieu qua cac ((((tuc va) OR (thuc va))) or (tuc xa)) dao dai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y lang xa hoi. hieu qua cac ((((tuc va) OR (thuc va))) OR (tuc xa)) dao dai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y lang xa hoi. hieu qua cac ((((tuc va) OR (thuc va))) or (tuc xa)) dao dai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y lang xa hoi. hieu qua cac ((((tuc va) OR (thuc va))) or (tuc xa)) dao dai cua tre*.