Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
su sach » so sach, vu sach
ky lang » ky dang, ky tang, tay lang
van cam » van nam, van lam, van cau
cam tuc » cam xuc, cam tu, nam thuc
tuc va » thuc va, truc va, tuc xa
va dan » ca dan, va dao, va dau
tai su » tai tu, lai su, tai du
tai so » tai sao, dai so, tai co

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