Perhaps you should try some spelling variations:
thieu hang » thieu khang, thieu quang, thi hang
phap thuc » phap thu, phap hoc, phap tu
thuc van » thuc vat, thuc dan, thuc va
su triet » su tien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
hieu van » hieu va, thien van, lieu va
van phap » ban phap, va phap, van phan
so sach » so sanh, bo sach, co sach
su viet » so viet
x hoi » xa hoi, o hoi, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach thieu hang ((x hoi) or (x ho)). hieu van phap thuc van hanh vai ((su triet) OR (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach thieu hang ((x hoi) OR (x ho)). hieu van phap thuc van hanh vai ((su triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach thieu hang ((x hoi) or (x ho)). hieu van phap thuc van hanh vai ((su triet) OR (su viet))".
• Adding a wildcard symbol may retrieve word variants: so sach thieu hang ((x hoi) or (x ho)). hieu van phap thuc van hanh vai ((su triet) OR (su viet))*.