Perhaps you should try some spelling variations:
dat hoang » dat hang, dang hoang, dai khoang
hoang van » hang va
nam thuc » nam thuoc, nam thu, nam tu
cua viet » ca viet, hoa viet, cua vat
bo sach » co sach, hoc sach
sach ky » sac ky, sach y, sach ty
nang xa » nang x, lang xa, nang ma
hieu he » hieu ve, hieu le, hieu hien
hiem he » hiem xe, thien he, hiem cho
van cua » vang cua, ban cua, dan 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 ky nang xa hoi. ((hieu he) OR (hiem he)) ((nam thuc) or (am thuc)) dat hoang van cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach ky nang xa hoi. ((hieu he) OR (hiem he)) ((nam thuc) OR (am thuc)) dat hoang van cua viet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach ky nang xa hoi. ((hieu he) OR (hiem he)) ((nam thuc) or (am thuc)) dat hoang van cua viet*".