Perhaps you should try some spelling variations:
xang van » dang van, tang van, nang van
lang van » dang van, tang van, hoang van
doan thi » dan thi, doanh tai, hoang thi
te sach » toc sach
doan vi » doan va, don vi, doan van
cua tre » cua te, cuu tre, cua triet
cac hoi » cac thoi, cac khoi, cau hoi
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ty ((xang van) OR (lang van)) hoi. hieu ve cac hoi va ((doan vi) or (doan thi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ty ((xang van) OR (lang van)) hoi. hieu ve cac hoi va ((doan vi) OR (doan thi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ty ((xang van) OR (lang van)) hoi. hieu ve cac hoi va ((doan vi) or (doan thi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ty ((xang van) OR (lang van)) hoi. hieu ve cac hoi va ((doan vi) or (doan thi)) cua tre*.