Perhaps you should try some spelling variations:
hieu van » thien van, lieu va, hieu ve
hanh sai » hanh san, hanh tai, danh sai
sai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cao hoc » co hoc, cho hoc, chat hoc
hieu va » lieu va, hieu qua
tu sach » thu sach, su sach, tu cach
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
te sach » toc sach
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) OR (te sach)) ky lang xa hoi. ((hieu van) or (hieu va)) cao hoc va hanh sai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky lang xa hoi. ((hieu van) OR (hieu va)) cao hoc va hanh sai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) ky lang xa hoi. ((hieu van) or (hieu va)) cao hoc va hanh sai cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) ky lang xa hoi. ((hieu van) or (hieu va)) cao hoc va hanh sai cua te*.