Perhaps you should try some spelling variations:
tai khoi » tai khoa, mai khoi, tao khoi
hanh vai » hanh vi, hanh va, hanh tai
tu sach » thu sach, su sach, te sach
cau luc » cau truc, cau phuc
ky tang » ky nang, ky dang, kho tang
vai cua » dai cua, hai cua, lai cua
dai hoi » dai hoc, dai hai, dai moi
hieu ve » hieu van
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
luc va » duc va, tuc va, loc va
cua tu » cua tuc, cua su, cua cu

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 ky tang ((tai khoi) or (dai hoi)). ((hieu ve) or (hieu va)) cau luc va hanh vai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky tang ((tai khoi) OR (dai hoi)). ((hieu ve) OR (hieu va)) cau luc va hanh vai cua tu.
• Adding a wildcard symbol may retrieve word variants: tu sach ky tang ((tai khoi) or (dai hoi)). ((hieu ve) or (hieu va)) cau luc va hanh vai cua tu*.