Perhaps you should try some spelling variations:
danh viet » anh viet, ninh viet, nang viet
danh kien » dinh kien, linh kien, van kien
hac thuc » hoc thuc, ha thuc, thach thuc
hieu van » hieu va, thien van, lieu va
so sach » so sanh, bo sach, co sach
thuc va » thuc vat, thuc dan, thuc day
van hac » van hoc, van ha, van hai
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
cuu tre » cua tre, cau tren, cau treo

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 y ((nang xa) or (nang ma)) hoi. hieu van hac thuc va ((danh kien) OR (danh viet)) cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((nang xa) OR (nang ma)) hoi. hieu van hac thuc va ((danh kien) OR (danh viet)) cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((nang xa) or (nang ma)) hoi. hieu van hac thuc va ((danh kien) OR (danh viet)) cuu tre".
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang xa) or (nang ma)) hoi. hieu van hac thuc va ((danh kien) OR (danh viet)) cuu tre*.