Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cuu thuc » cuu tac
nang xa » nang x, lang xa, nang ma
so sach » so sanh, bo sach, co sach
van cuu » van cau, van chu, van cu
thuc va » thuc vat, thuc dan, thuc day
va dinh » van dinh, va kinh, va tinh
hai cau » hai chau, hai chu, hoi cau
hai hau » hai chau, dai hau, hai hai
vu sach » vu bach, su sach, vu khach
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((vu sach) or (so sach)) y nang xa hoi. hieu van cuu thuc va dinh ((hai cau) OR (hai hau)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((vu sach) OR (so sach)) y nang xa hoi. hieu van cuu thuc va dinh ((hai cau) OR (hai hau)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((vu sach) or (so sach)) y nang xa hoi. hieu van cuu thuc va dinh ((hai cau) OR (hai hau)) triet".
• Adding a wildcard symbol may retrieve word variants: ((vu sach) or (so sach)) y nang xa hoi. hieu van cuu thuc va dinh ((hai cau) OR (hai hau)) triet*.