Perhaps you should try some spelling variations:
trong van » trong cac
sanh thu » sach thu, san thu, doanh thu
tang van » dang van, hoang van, tang luan
qua pham » quan pham, quy pham, qua cham
pham duy » pham duc
vat hanh » vat thanh, van hanh, va hanh
so sanh » do sanh
vi cua » vai cua, di cua
cua te » cua tu

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 thu ((tang van) or (trong van)) hoi. hieu qua pham duy vat hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sanh thu ((tang van) OR (trong van)) hoi. hieu qua pham duy vat hanh vi cua te.
• Adding a wildcard symbol may retrieve word variants: so sanh thu ((tang van) or (trong van)) hoi. hieu qua pham duy vat hanh vi cua te*.