Perhaps you should try some spelling variations:
gia thuc » va thuc, gia tac, gia muc
hanh vai » hanh vi, hanh va, hanh tai
su sach » so sach, vu sach
xang xa » lang xa, mang xa, dang xay
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
sach le » cach le, sach de, sach lo
gia duc » giao duc, gia muc, gia dung
ang xa » lang xa, mang xa, dang xay
vai va » mai va, dai va, hai va
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: su sach le ((xang xa) OR (ang xa)) hoi. hieu va ((gia duc) or (gia thuc)) va hanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach le ((xang xa) OR (ang xa)) hoi. hieu va ((gia duc) OR (gia thuc)) va hanh vai va thiet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach le ((xang xa) OR (ang xa)) hoi. hieu va ((gia duc) or (gia thuc)) va hanh vai va thiet".
• Adding a wildcard symbol may retrieve word variants: su sach le ((xang xa) OR (ang xa)) hoi. hieu va ((gia duc) or (gia thuc)) va hanh vai va thiet*.