Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cau treo » cau theo, cau triet, cau trieu
nang hai » hang hai, nang tai, dang hai
hieu van » hieu va, thien van, lieu va
sang tao » hang tai
tao hoi » tao khoi, tao boi, tay hoi
va nang » van nang, da nang, cam nang
sach tu » sach thu, cach tu, sach ty
nam tu » nam thu, nam thuc

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 tu)) sang tao hoi. hieu van nam tu va nang hai ((cau treo) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach y) OR (sach tu)) sang tao hoi. hieu van nam tu va nang hai ((cau treo) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: su ((sach y) or (sach tu)) sang tao hoi. hieu van nam tu va nang hai ((cau treo) or (cau tren))*.