Perhaps you should try some spelling variations:
hoc sach » hoc cac, hoc anh
truc van » thuc van, truc ban, truc dan
lang van » dang van, tang van, hoang van
truc va » thuc va, thuc vat, trung va
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
van hoi » van hoa, van hoc, van hoe
ve cam » ve cham, ve cac, va cam
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 sinh)) y lang van hoi. hieu ve cam ((truc van) or (truc va)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc sach) OR (hoc sinh)) y lang van hoi. hieu ve cam ((truc van) OR (truc va)) hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc sach) OR (hoc sinh)) y lang van hoi. hieu ve cam ((truc van) or (truc va)) hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((hoc sach) OR (hoc sinh)) y lang van hoi. hieu ve cam ((truc van) or (truc va)) hanh vi cua tre*.