Perhaps you should try some spelling variations:
sang mai » sang ma, sang tai, lang mai
van hanh » van thanh, van anh, van ban
ban hanh » ban hang
te sach » toc sach
sach ty » sach y, sach tu, sach thu
ty sang » ty xang, ty hang, duy sang
mai hoi » mai khoi, dai hoi, lai hoi
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 sang mai hoi. hieu qua hai duc ((van hanh) OR (ban hanh)) dai cua tuc~.
• Adding a wildcard symbol may retrieve word variants: te sach ty sang mai hoi. hieu qua hai duc ((van hanh) or (ban hanh)) dai cua tuc*.