Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
cau triet » cau trieu, su triet, cua triet
nam thuy » nam thu, nam thuc, nam thue
thuy van » thuy san, thuc van, chu van
doanh va » doan va, doanh tai, doanh cua
tu sach » thu sach, su sach, te sach
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
va cau » van cau, va cac, va dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach y ((nang xa) OR (nang ma)) hoi. hieu va nam thuy van doanh va cau triet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y ((nang xa) OR (nang ma)) hoi. hieu va nam thuy van doanh va cau triet".
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang xa) OR (nang ma)) hoi. hieu va nam thuy van doanh va cau triet*.