Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van anh
van thanh » ban thanh, van tuan
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
lang xa » lang ha, dang xay, lang van
qua cam » qua cham, qua cac, qua ca
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet

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 ((nang ma) or (lang xa)) hoi. hieu qua cam xuc ((van doanh) OR (van thanh)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang ma) OR (lang xa)) hoi. hieu qua cam xuc ((van doanh) OR (van thanh)) tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang ma) or (lang xa)) hoi. hieu qua cam xuc ((van doanh) OR (van thanh)) tai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang ma) or (lang xa)) hoi. hieu qua cam xuc ((van doanh) OR (van thanh)) tai cua tre*.