Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc cac, hoc anh
thuc dan » thuc hanh, hoc dan, thuc vat
lang van » dang van, tang van, hoang van
thuc va » thuc vat, thuc day
qua cac » cua cac
so sanh » do sanh
van hoi » van hoa, van hoc, van hoe
cua tuc » cua duc, cua tu, cua thuoc
o lang » hoa lang, hoi lang
vi cua » vai cua, di cua

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