Perhaps you should try some spelling variations:
vat hanh » vat thanh, van hanh, va hanh
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, te sach, tu cach
su sach » so sach, vu sach
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
hieu ve » hieu va, hieu van
vai va » mai va, dai va, hai va
ve am » va am
thiet » thieu

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 (su sach)) ky lang ha noi. hieu ve am (thuc OR thu) vat hanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky lang ha noi. hieu ve am (thuc OR thu) vat hanh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (su sach)) ky lang ha noi. hieu ve am (thuc OR thu) vat hanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (su sach)) ky lang ha noi. hieu ve am (thuc OR thu) vat hanh vai va thiet*.