Perhaps you should try some spelling variations:
thien van » thi van
hanh lai » hanh lam, hanh tai, thanh lap
cua viet » ca viet, hoa viet, cua vat
sach ky » sach y, sach ty, sach kem
van cac » van hac, van cau, van bac
lai cua » dai cua, hai cua, lai chau
sac ky » cac ky, sai ky
nang o » nang co, nang ho, nang ro
luc va » tuc va, loc va
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: vu ((sach ky) OR (sac ky)) nang o hoi. thien van cac ((luc va) or (duc va)) hanh lai cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach ky) OR (sac ky)) nang o hoi. thien van cac ((luc va) OR (duc va)) hanh lai cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach ky) OR (sac ky)) nang o hoi. thien van cac ((luc va) or (duc va)) hanh lai cua viet".
• Adding a wildcard symbol may retrieve word variants: vu ((sach ky) OR (sac ky)) nang o hoi. thien van cac ((luc va) or (duc va)) hanh lai cua viet*.