Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
cau theo » cau thi, cau tao
hanh hai » thanh hai, nhanh hai, hang hai
xa hanh » xa thanh, xa khanh, va hanh
cam tuc » cam xuc, cam tu, nam thuc
tang ma » mang may, tang van
ly tang » le tang, ly hang, ly vang
van cam » van nam, van lam, van cau
ma hoi » mai hoi, xa hoi, ma hoa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((so sanh) or (do sanh)) ly tang ma hoi. hieu van cam tuc xa hanh hai ((cau theo) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((so sanh) OR (do sanh)) ly tang ma hoi. hieu van cam tuc xa hanh hai ((cau theo) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: ((so sanh) or (do sanh)) ly tang ma hoi. hieu van cam tuc xa hanh hai ((cau theo) or (cau tren))*.