Perhaps you should try some spelling variations:
hieu vien » hieu hien, hieu viec, thieu nien
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » van thanh, ban hanh, van anh
sang dai » sang tai, lang dai, sang mai
vien da » vien dai, hien dai
vai cua » dai cua, hai cua, lai cua
va hanh » va thanh, va danh, ban hanh
tu sach » su sach, te sach, tu cach
dai hai » dai han, dai hoi, dai tai
ky sang » ky nang, ky dang, ky tang
da tuc » dao tuc, va tuc, da tac
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: ((tu sach) or (thu sach)) ky sang dai hai. hieu vien da tuc ((va hanh) or (van hanh)) vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky sang dai hai. hieu vien da tuc ((va hanh) OR (van hanh)) vai cua te.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky sang dai hai. hieu vien da tuc ((va hanh) or (van hanh)) vai cua te*.