Perhaps you should try some spelling variations:
kho tang » cao tang
tu sach » thu sach, su sach, te sach
vai cua » dai cua, hai cua, lai cua
dan vai » dan va, dan tai, dan vat
hieu ve » hieu va, hieu van
ky tang » ky nang, ky dang, ky trong
ma hoi » mai hoi, xa hoi, ma hoa
cac tu » cac thu, cach tu, cac du
va dan » ca dan, va dao, va dau
cua te » cua tu

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 tang) OR (kho tang)) ma hoi. ((hieu ve) or (hieu qua)) cac tu va dan vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky tang) OR (kho tang)) ma hoi. ((hieu ve) OR (hieu qua)) cac tu va dan vai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky tang) OR (kho tang)) ma hoi. ((hieu ve) or (hieu qua)) cac tu va dan vai cua te*".