Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
vanh dai » van dai, vanh tai, lanh dao
ty nang » ky nang, ty xang, ty hang
su sach » so sach, vu sach
van cau » van dau, van hau, van chat
cau tuc » cau truc, cau tu, cau luc
va vanh » va van, va danh, va hanh
tu sach » thu sach, te sach, tu cach
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) OR (su sach)) ty nang ((ma hoa) or (xa hoi)). hieu van cau tuc va vanh dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ty nang ((ma hoa) OR (xa hoi)). hieu van cau tuc va vanh dai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ty nang ((ma hoa) or (xa hoi)). hieu van cau tuc va vanh dai su triet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ty nang ((ma hoa) or (xa hoi)). hieu van cau tuc va vanh dai su triet*.