Perhaps you should try some spelling variations:
dat hoang » dat hang, dang hoang, dai khoang
hoang hai » hoang thi, hoang van
hoc sach » hoc sinh, hoc cac, hoc anh
nam thuc » nam thuoc, nam thu, nam tu
cua viet » ca viet, hoa viet, cua vat
bo sach » co sach
nang xa » nang x, lang xa, nang ma
hieu he » hieu ve, hiem he, hieu le
hai cua » thai cua, dai cua, hoi cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((bo sach) OR (hoc sach)) ky nang xa hoi. hieu he ((nam thuc) or (am thuc)) dat hoang hai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((bo sach) OR (hoc sach)) ky nang xa hoi. hieu he ((nam thuc) OR (am thuc)) dat hoang hai cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((bo sach) OR (hoc sach)) ky nang xa hoi. hieu he ((nam thuc) or (am thuc)) dat hoang hai cua viet*".