Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hieu van » hieu va, thien van, lieu va
hanh tai » thanh tai, hang tai, han tai
va hanh » van hanh, va thanh, va danh
hoc duc » hoc duoc, hoc nuoc, hoc thuc
hac duc » ha duc, thach duc, pham duc
sach ty » sach y, sach thu, xach tay
nang xa » nang x, lang xa, nang ma
sach tu » sach thu, cach tu, sach uu
tai su » tai so, tai tu, lai su

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

• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach tu)) nang xa hoi. hieu van ((hac duc) OR (hoc duc)) va hanh tai su triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) OR (sach tu)) nang xa hoi. hieu van ((hac duc) or (hoc duc)) va hanh tai su triet~".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) OR (sach tu)) nang xa hoi. hieu van ((hac duc) or (hoc duc)) va hanh tai su triet*.