Perhaps you should try some spelling variations:
thieu nien » thien nhien
hieu vien » hieu hien, hieu viec, hieu tieng
van hanh » van thanh, ban hanh, van anh
hanh dai » hanh tai, hanh dao, vanh dai
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
ky mang » ky nang, ke mang, ky dang
may hoi » may thoi, tay hoi, mai hoi
cac dai » cac dan, cac bai, can dai
dai van » dao van, dai han, dai va
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ky mang may hoi. ((hieu vien) or (thieu nien)) cac dai van hanh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky mang may hoi. ((hieu vien) OR (thieu nien)) cac dai van hanh dai cua te.
• Adding a wildcard symbol may retrieve word variants: so sach ky mang may hoi. ((hieu vien) or (thieu nien)) cac dai van hanh dai cua te*.