Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
cac thuc » cach thuc, cac thu, can thuc
sach ky » sac ky, sach y, sach ty
cao hoi » cau hoi, co hoi, cao hoc
van cac » van hac, van cau, van bac
thuc va » thuc vat, thuc dan, thuc day
va tinh » may tinh
gia cua » gian cua, giau cua, nghia cua
gia cuc » gia muc, gia duc, gia suc

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (cac ky)) nang cao hoi. hieu van cac thuc va tinh ((gia cua) OR (gia cuc)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (cac ky)) nang cao hoi. hieu van cac thuc va tinh ((gia cua) OR (gia cuc)) tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (cac ky)) nang cao hoi. hieu van cac thuc va tinh ((gia cua) OR (gia cuc)) tre".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (cac ky)) nang cao hoi. hieu van cac thuc va tinh ((gia cua) OR (gia cuc)) tre*.