Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
ban doanh » san doanh, ban danh, toan doanh
lang van » dang van, tang van, hoang van
tu sach » thu sach, su sach, te sach
cam cuc » cam xuc, cham cuu, pham cuc
hai cua » thai cua, dai cua, hoi cua
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
lang ha » long ha
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam

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 ky ((lang ha) or (lang van)) hoi. hieu ve cam cuc ((ban doanh) OR (van doanh)) hai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((lang ha) OR (lang van)) hoi. hieu ve cam cuc ((ban doanh) OR (van doanh)) hai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((lang ha) or (lang van)) hoi. hieu ve cam cuc ((ban doanh) OR (van doanh)) hai cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((lang ha) or (lang van)) hoi. hieu ve cam cuc ((ban doanh) OR (van doanh)) hai cua tre*.