Perhaps you should try some spelling variations:
dai tren » dat tren, dau tren, dan tren
dang xay » dang van, van xay
va hanh » van hanh, va thanh, va danh
cau xuc » cau luc, cau truc, chat xuc
tu sach » thu sach, su sach, te sach
mang xa » lang xa, mang may, mang cua
hieu va » lieu va, hieu qua
vi dai » si dai, li dai, vien dai

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((mang xa) or (dang xay)) hoi. hieu va ((cau xuc) or (cam xuc)) va hanh vi dai tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((mang xa) OR (dang xay)) hoi. hieu va ((cau xuc) OR (cam xuc)) va hanh vi dai tren.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((mang xa) or (dang xay)) hoi. hieu va ((cau xuc) or (cam xuc)) va hanh vi dai tren*.