Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
truc van » truc va, thuc van, truc ban
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
dang ha » dong ha, dung ha, tang ha
lang ha » long ha
va cau » van cau, va cac, va dau
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: ((su sach) or (thu hoach)) ky ((dang ha) OR (lang ha)) hoi. hieu va cau truc van hanh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (thu hoach)) ky ((dang ha) OR (lang ha)) hoi. hieu va cau truc van hanh vai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (thu hoach)) ky ((dang ha) OR (lang ha)) hoi. hieu va cau truc van hanh vai cua te".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (thu hoach)) ky ((dang ha) OR (lang ha)) hoi. hieu va cau truc van hanh vai cua te*.