Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
hoi lang » hoa lang, hoi dan
cac thuc » cach thuc, cac thu, can thuc
lang van » dang van, tang van, hoang van
so sanh » do sanh
van hoi » van hoa, van hoc, van hoe
qua cac » cua cac
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
cua tuc » cua tu, cua thuoc, luat tuc
cua duc » cua nuoc, cua quoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc sach) or (so sanh)) hoi lang van hoi. hieu qua cac thuc va hanh vi ((cua tuc) OR (cua duc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (so sanh)) hoi lang van hoi. hieu qua cac thuc va hanh vi ((cua tuc) OR (cua duc)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) or (so sanh)) hoi lang van hoi. hieu qua cac thuc va hanh vi ((cua tuc) OR (cua duc))".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (so sanh)) hoi lang van hoi. hieu qua cac thuc va hanh vi ((cua tuc) OR (cua duc))*.