Perhaps you should try some spelling variations:
sach truc » sach tren, sach thu, sach thue
cach thuc » anh thuc
dan trong » ban trong, dat trong, dao trong
hieu thuc » hieu thuoc, hien thuc, lieu thuc
thuc dan » thuc hanh, hoc dan, thuc vat
hieu tuc » hieu luc, hieu thuoc, lieu thuc
cac thu » cac thoi

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 truc) or (((cach thuc) or (cac thu)))) thuc dan trong ((hieu thuc) or (hieu tuc)) giai~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach truc) OR (((cach thuc) OR (cac thu)))) thuc dan trong ((hieu thuc) OR (hieu tuc)) giai.
• Adding a wildcard symbol may retrieve word variants: tu ((sach truc) or (((cach thuc) or (cac thu)))) thuc dan trong ((hieu thuc) or (hieu tuc)) giai*.