Perhaps you should try some spelling variations:
dau thuc » dan thuc, dai thuc, dam thuc
vat dinh » va dinh, van dinh, vat sinh
hieu van » hieu va, thien van, lieu va
hai hau » hai chau, dai hau, hai hai
hai cau » hai chau, hai chu, hoi cau
su sach » vu sach
nang xa » nang x, lang xa, nang ma
so sach » so sanh, bo sach, co sach
van dau » van dao, phan dau
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: ((su sach) or (so sach)) y nang xa hoi. hieu van dau thuc vat dinh ((hai cau) OR (hai hau)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (so sach)) y nang xa hoi. hieu van dau thuc vat dinh ((hai cau) OR (hai hau)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) or (so sach)) y nang xa hoi. hieu van dau thuc vat dinh ((hai cau) OR (hai hau)) triet".
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (so sach)) y nang xa hoi. hieu van dau thuc vat dinh ((hai cau) OR (hai hau)) triet*.