Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
lang van » dang van, tang van, hoang van
van dung » van dong, xay dung, tin dung
tuc van » thuc van, truc van, tuc va
cuu tre » cua tre, cau treo
lang ha » long ha
hieu va » lieu va, hieu qua
cam tuc » cam xuc, cam tu, nam thuc
tu sai » tu bai, tu san, tu cai
sai ky » sac ky
va cam » va cham, va cac, va cao

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sai ky ((lang van) or (lang ha)) hoi. hieu va cam tuc van dung tai ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sai ky ((lang van) OR (lang ha)) hoi. hieu va cam tuc van dung tai ((cuu tre) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sai ky ((lang van) or (lang ha)) hoi. hieu va cam tuc van dung tai ((cuu tre) OR (cau tren))".
• Adding a wildcard symbol may retrieve word variants: tu sai ky ((lang van) or (lang ha)) hoi. hieu va cam tuc van dung tai ((cuu tre) OR (cau tren))*.