Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
cau theo » cau thi, cau tao
hanh hai » thanh hai, nhanh hai, hang hai
hieu van » hieu va, thien van, lieu va
doanh ly » doanh va, dinh ly, doanh _
nang ma » tang ma, sang ma, nang cao
sanh ly » sinh ly, khanh ly, lanh lay
van cam » van nam, van lam, van cau
cam tuc » cam xuc, cam tu, nam thuc
xa hanh » xa thanh, xa khanh, va hanh
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 ly) OR (doanh ly)) nang 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 ly) OR (doanh ly)) nang ma 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) OR (doanh ly)) nang ma hoi. hieu van cam tuc xa hanh hai ((cau theo) or (cau tren))".
• Adding a wildcard symbol may retrieve word variants: so ((sanh ly) OR (doanh ly)) nang ma hoi. hieu van cam tuc xa hanh hai ((cau theo) or (cau tren))*.