Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
dang xay » dang van, van xay
hieu cua » hieu qua, dieu cua, bieu cua
sach thu » sach thue, sach thieu, sach tham
xay hoi » xa hoi, tay hoi, cay phoi
cua dam » cua dan, cua dai, cua tam
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
dam tu » nam tu, cam tu, tam tu

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

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