Perhaps you should try some spelling variations:
hanh vai » hanh vi, hanh va, hanh tai
ban hanh » ban hang
tu sach » thu sach, su sach, te sach
hieu va » lieu va, hieu qua
vai cua » dai cua, hai cua, lai cua
hieu ve » hieu van
duc ban » duc tan, duc van, dua ban
cac duc » cac du, cao duc, cac dac
cua te » cua tu
y nang » ky nang, ly nang, may nang
v nang » va nang, vu nang, van nang

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 ((y nang) or (v nang)) xa hoi. ((hieu ve) OR (hieu va)) cac duc ban hanh vai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (v nang)) xa hoi. ((hieu ve) OR (hieu va)) cac duc ban hanh vai cua te*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((y nang) or (v nang)) xa hoi. ((hieu ve) OR (hieu va)) cac duc ban hanh vai cua te*".