Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
hanh vai » hanh vi, hanh va, hanh tai
cam thuc » am thuc, nam thuc, can thuc
va hanh » van hanh, va thanh, va danh
cam thu » nam thu, cac thu, ca thu
su sach » so sach, vu sach
hieu ve » hieu va
nang ma » tang ma, sang ma, nang cao
y nang » ky nang, ly nang, v nang
ma hoi » mai hoi, xa hoi, ma hoa
vai su » va su, van su, lai su

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 y nang ma hoi. ((hieu ve) OR (hieu van)) ((cam thuc) or (cam thu)) va hanh vai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang ma hoi. ((hieu ve) OR (hieu van)) ((cam thuc) OR (cam thu)) va hanh vai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang ma hoi. ((hieu ve) OR (hieu van)) ((cam thuc) or (cam thu)) va hanh vai su triet".
• Adding a wildcard symbol may retrieve word variants: su sach y nang ma hoi. ((hieu ve) OR (hieu van)) ((cam thuc) or (cam thu)) va hanh vai su triet*.