Perhaps you should try some spelling variations:
gianh lai » gian lan
hieu van » hieu va, thien van, lieu va
danh lai » danh sai, dinh lam, hanh lam
chau tre » chay tren, chau tho, cho tre
sach ty » sach y, sach tu, sach thu
cao hoi » cau hoi, co hoi, cao hoc
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
sac ky » cac ky, sai ky

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sac ky)) nang cao hoi. hieu van cam duc va ((danh lai) OR (gianh lai)) chau tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) or (sac ky)) nang cao hoi. hieu van cam duc va ((danh lai) OR (gianh lai)) chau tre~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sac ky)) nang cao hoi. hieu van cam duc va ((danh lai) OR (gianh lai)) chau tre*.