Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
vat doanh » van doanh, vay doanh, va doanh
thu sach » tu sach, thuat sach, thuoc sach
cua viet » ca viet, hoa viet, cua vat
nang noi » nang doc
sach ty » sach y, sach tu, sach thu
nang co » nang cao, nang doc, nang hoc
van cua » vang cua, ban cua, dan cua
va cam » va cham, va cac, va cao
va am » va lam

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ty ((nang co) OR (nang noi)) hoi. hieu ((va am) OR (va cam)) thuc vat doanh van cua viet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ty ((nang co) or (nang noi)) hoi. hieu ((va am) OR (va cam)) thuc vat doanh van cua viet~".
• Adding a wildcard symbol may retrieve word variants: thu sach ty ((nang co) or (nang noi)) hoi. hieu ((va am) OR (va cam)) thuc vat doanh van cua viet*.