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
so sanh » do sanh
sanh ly » sinh ly, doanh ly, khanh ly
ly nang » ky nang, ly hang, ly vang
van cam » van nam, van lam, van cau
ma hoi » mai hoi, ma hoa, me hoi

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 ly nang ((ma hoi) OR (xa 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 ly nang ((ma hoi) OR (xa hoi)). hieu van cam tuc xa hanh hai ((cau theo) OR (cau tren)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sanh ly nang ((ma hoi) OR (xa hoi)). hieu van cam tuc xa hanh hai ((cau theo) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: so sanh ly nang ((ma hoi) OR (xa hoi)). hieu van cam tuc xa hanh hai ((cau theo) or (cau tren))*.