Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cay phoi » cap phoi, tay hoi, cay cho
hieu van » hieu va, thien van, lieu va
luc van » luoc van, luu van, duc van
van cau » van dau, van hau, van chat
tu sach » thu sach, su sach, te sach
lam luc » lao luc, lam duoc
ky danh » ky anh
ky dang » ky nang
van lam » van nam
va cau » va cac, va dau, va cao

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 luc van hanh ((va cau) OR (van 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 luc van hanh ((va cau) OR (van 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 luc van hanh ((va cau) OR (van cau)) trieu*".