Perhaps you should try some spelling variations:
thien van » thi van
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, lieu va, hieu ve
tuc van » thuc van, truc van, tuc va
hoc tuc » hoc thuc, hoc truc, hoc tu
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa
hai ve » hoai ve, hai va, hoi ve
hai vu » hai va

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ty nang ma hoi. ((hieu van) or (thien van)) hoc tuc van hanh ((hai ve) or (hai vu)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ma hoi. ((hieu van) OR (thien van)) hoc tuc van hanh ((hai ve) OR (hai vu)) triet.
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ma hoi. ((hieu van) or (thien van)) hoc tuc van hanh ((hai ve) or (hai vu)) triet*.