Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
day doanh » vay doanh, dao doanh, day danh
thuc day » thuc dan, thuc vat
tu sach » thu sach, te sach, tu cach
ca viet » va viet, co viet, hoa viet
su sach » so sach, vu sach
he nam » ha nam, nghe nam
van ca » van cau, van cua, dan ca
ve nam » va nam, le nam, te nam
x hoi » xa hoi, o hoi, x ho

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) OR (su sach)) ky nang x hoi. hieu ((ve nam) or (he nam)) thuc day doanh van ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (su sach)) ky nang x hoi. hieu ((ve nam) OR (he nam)) thuc day doanh van ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) OR (su sach)) ky nang x hoi. hieu ((ve nam) or (he nam)) thuc day doanh van ca viet".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) OR (su sach)) ky nang x hoi. hieu ((ve nam) or (he nam)) thuc day doanh van ca viet*.