Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu va » lieu va, hieu qua
danh vi » hanh vi, dinh vi, danh di
te sach » toc sach
ly vang » ly hang, ly van, ly quang
va cham » va chat, va tham
xac va » tac va, ac va, bac va
vi cau » va cau, ve cau, di cau

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 ((vu quang) or (ly vang)) x ho. hieu va cham ((xac va) or (tuc xa)) danh vi cau tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((vu quang) OR (ly vang)) x ho. hieu va cham ((xac va) OR (tuc xa)) danh vi cau tren.
• Adding a wildcard symbol may retrieve word variants: te sach ((vu quang) or (ly vang)) x ho. hieu va cham ((xac va) or (tuc xa)) danh vi cau tren*.