Perhaps you should try some spelling variations:
nha thuoc » nha nuoc, nhan thuc, nha hoc
hieu van » thien van, lieu va, hieu ve
thuoc va » thuc va, thuoc ma, thuong va
tu sach » thu sach, su sach, tu cach
hanh di » hanh vi, hanh de, hang di
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
ca viet » va viet, co viet, hoa viet
nang xa » nang x, lang xa, nang ma
lo nang » ho nang, ly nang, loai nang
te sach » toc sach
di ca » di cau, di cua, doi ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) OR (te sach)) lo nang xa hoi. ((hieu van) or (hieu va)) nha thuoc va hanh di ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) lo nang xa hoi. ((hieu van) OR (hieu va)) nha thuoc va hanh di ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (te sach)) lo nang xa hoi. ((hieu van) or (hieu va)) nha thuoc va hanh di ca viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (te sach)) lo nang xa hoi. ((hieu van) or (hieu va)) nha thuoc va hanh di ca viet*.