Perhaps you should try some spelling variations:
cac khoi » cac thoi, cac khoan, cach thoi
te sach » toc sach
hieu va » lieu va, hieu qua
hanh va » hang va, hanh vi
va hanh » van hanh, va thanh, va danh
hieu ve » hieu van
cau tuc » cau truc, cau tu, cau luc
va cua » va chua, via cua, ca cua
tuc va » thuc va, truc va, tuc xa
cua su » qua su
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y nang ((ma hoi) or (cac khoi)). ((hieu ve) or (hieu va)) cau tuc va hanh va cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y nang ((ma hoi) OR (cac khoi)). ((hieu ve) OR (hieu va)) cau tuc va hanh va cua su.
• Adding a wildcard symbol may retrieve word variants: te sach y nang ((ma hoi) or (cac khoi)). ((hieu ve) or (hieu va)) cau tuc va hanh va cua su*.