Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
va cau » van cau, va cac, va dau
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
cua tu » cua tuc, cua su, cua cu

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 ky nang x ho. hieu va cau ((luc va) or (tuc va)) doanh van ((cua te) OR (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky nang x ho. hieu va cau ((luc va) OR (tuc va)) doanh van ((cua te) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky nang x ho. hieu va cau ((luc va) or (tuc va)) doanh van ((cua te) OR (cua tu))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky nang x ho. hieu va cau ((luc va) or (tuc va)) doanh van ((cua te) OR (cua tu))*.