Perhaps you should try some spelling variations:
dau tren » dau tien, dat tren, dau tieng
cau tren » cu tren, ca tren, cau treo
hieu van » hieu va, thien van, lieu va
dan thi » dang thi, tran thi, dinh thi
cuu tre » cua tre, cau treo
te sach » toc sach
sach ky » sac ky, sach y, sach ty
nam xuc » cam xuc, nam xua, nam thuc
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
xuc va » duc va, tuc va, luc va
va dan » ca dan, va dao, va dau

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 ky dang xa hoi. hieu van nam xuc va dan thi ((cuu tre) or (((cau tren) OR (dau tren))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky dang xa hoi. hieu van nam xuc va dan thi ((cuu tre) OR (((cau tren) OR (dau tren)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky dang xa hoi. hieu van nam xuc va dan thi ((cuu tre) or (((cau tren) OR (dau tren))))".
• Adding a wildcard symbol may retrieve word variants: te sach ky dang xa hoi. hieu van nam xuc va dan thi ((cuu tre) or (((cau tren) OR (dau tren))))*.