Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh dai » hanh tai, hanh dao, vanh dai
ve cham » va cham, ve chat, vu cham
va hanh » van hanh, va thanh, va danh
truc va » thuc va, thuc vat, trung va
ve cam » ve cac, va cam, ve cai
dai su » dai sua, dai so, dan su
x hoi » xa hoi, o hoi, x ho

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 2) or (sach y)) nang x hoi. hieu ((ve cam) OR (ve cham)) truc va hanh dai su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach 2) OR (sach y)) nang x hoi. hieu ((ve cam) OR (ve cham)) truc va hanh dai su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach 2) or (sach y)) nang x hoi. hieu ((ve cam) OR (ve cham)) truc va hanh dai su triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach 2) or (sach y)) nang x hoi. hieu ((ve cam) OR (ve cham)) truc va hanh dai su triet*.