Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vanh dai » van dai, vanh tai, lanh dao
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
ty nang » ky nang, ty xang, ty hang
van dau » van dao, phan dau
dau tuc » dau tu, dao tuc, cau truc
va vanh » va van, va danh, va hanh
tuc va » thuc va, truc va, tuc xa
dai su » dai sua, dai so, dan su

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 ty nang ((ma hoa) or (xa hoi)). hieu van dau tuc va vanh dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang ((ma hoa) OR (xa hoi)). hieu van dau tuc va vanh dai su triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang ((ma hoa) or (xa hoi)). hieu van dau tuc va vanh dai su triet*.