Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
lam thuoc » nam thuoc, am thuc, cay thuoc
lam duoc » nam duoc, luat duoc, tao duoc
ma doanh » va doanh, hoa doanh, van doanh
hieu van » hieu va, thien van, lieu va
te sach » toc sach
ky danh » ky anh, ky dang
ky lang » ky nang, ky dang, ky tang
ca viet » va viet, co viet, hoa viet
van ca » van cau, van cua, dan ca

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((ky lang) or (ky danh)) xa hoi. hieu van ((lam duoc) OR (lam thuoc)) ma doanh van ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((ky lang) OR (ky danh)) xa hoi. hieu van ((lam duoc) OR (lam thuoc)) ma doanh van ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((ky lang) or (ky danh)) xa hoi. hieu van ((lam duoc) OR (lam thuoc)) ma doanh van ca viet".
• Adding a wildcard symbol may retrieve word variants: te sach ((ky lang) or (ky danh)) xa hoi. hieu van ((lam duoc) OR (lam thuoc)) ma doanh van ca viet*.