Perhaps you should try some spelling variations:
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
sang xa » song xa, lang xa, sang ma
qua hai » qua hoat
hai duc » hoai duc, mai duc, ha duc
cua tuc » cua duc, cua tu, cua thuoc

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 (sach tu)) sang xa hoi. hieu qua hai duc ((van hanh) OR (ban hanh)) dai cua tuc~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) OR (sach tu)) sang xa hoi. hieu qua hai duc ((van hanh) or (ban hanh)) dai cua tuc~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) OR (sach tu)) sang xa hoi. hieu qua hai duc ((van hanh) or (ban hanh)) dai cua tuc*.