Perhaps you should try some spelling variations:
dan doanh » van doanh, san doanh, ban doanh
doanh van » doan van, doanh va, doanh ban
cua triet » cua viet, su triet, va triet
sach thi » sach thu, sach tai, sach thieu
thi sang » thi nang, thi hang, thi song
nam thuc » nam thuoc, am thuc, nam thu
thuc dan » thuc hanh, hoc dan, thuc vat
su sach » so sach, vu sach
sang ma » tang ma, nang ma, sang tao
hieu ve » hieu va, hieu van
van cua » vang cua, ban cua, dan cua
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: su sach thi sang ma hoi. ((hieu ve) or (hieu qua)) nam thuc dan doanh van cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thi sang ma hoi. ((hieu ve) OR (hieu qua)) nam thuc dan doanh van cua triet.
• Adding a wildcard symbol may retrieve word variants: su sach thi sang ma hoi. ((hieu ve) or (hieu qua)) nam thuc dan doanh van cua triet*.