Perhaps you should try some spelling variations:
cau trieu » cac trieu, cau triet, chua trieu
cay phoi » cap phoi, tay hoi, cay cho
hieu van » hieu va, thien van, lieu va
hanh va » hang va, hanh vi
duoc ma » duoc lam
duoc va » nuoc va, duc va, duong va
tu sach » thu sach, su sach, te sach
ky danh » ky anh
ky dang » ky nang
van lam » van nam
va cau » van cau, va cac, va dau

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 dang) or (ky danh)) cay phoi. hieu van lam ((duoc va) OR (duoc ma)) hanh va cau trieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky dang) OR (ky danh)) cay phoi. hieu van lam ((duoc va) OR (duoc ma)) hanh va cau trieu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((ky dang) or (ky danh)) cay phoi. hieu van lam ((duoc va) OR (duoc ma)) hanh va cau trieu".
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky dang) or (ky danh)) cay phoi. hieu van lam ((duoc va) OR (duoc ma)) hanh va cau trieu*.