Perhaps you should try some spelling variations:
thien van » thi van
thu sach » tu sach, thuat sach, thuoc sach
hieu van » hieu va, lieu va, hieu ve
doan vi » doan va, don vi, doan thi
sach ky » sac ky, sach y, sach ty
lam tuc » lam thuoc, lam truoc, luat tuc
luu tre » luu tru, cuu tre, luy tre
tuc va » thuc va, truc va, tuc xa
dan vi » don vi, dan va, gan vi
nang o » nang co, nang ho, nang ro
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ky nang o hoi. ((hieu van) or (thien van)) lam tuc va ((dan vi) OR (doan vi)) luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang o hoi. ((hieu van) OR (thien van)) lam tuc va ((dan vi) OR (doan vi)) luu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ky nang o hoi. ((hieu van) or (thien van)) lam tuc va ((dan vi) OR (doan vi)) luu tre*".