Perhaps you should try some spelling variations:
hoc sach » hoc sinh, hoc anh
thuc van » thuc vat, thuc dan, thuc hanh
lang van » dang van, tang van, hoang van
thuc va » thuc vat, thuc dan, thuc day
hieu ve » hieu va, hieu van
hoc cac » hoc cao
van hoi » van hoa, van hoc, van hoe
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
y lang » o lang, _ lang, tay 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 (hoc cac)) y lang van hoi. hieu ve cac ((thuc van) or (thuc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (hoc cac)) y lang van hoi. hieu ve cac ((thuc van) OR (thuc va)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) or (hoc cac)) y lang van hoi. hieu ve cac ((thuc van) or (thuc va)) hanh vi cua tre*.