Perhaps you should try some spelling variations:
doanh van » doan van, doanh va, doanh ban
sach ky » sach y, sach ty, sach kem
qua cau » quan cau, qua cac, qua ca
van cua » vang cua, ban cua, dan cua
sac ky » cac ky, sai ky
luc va » duc va, loc va
tuc va » thuc va, truc va, tuc xa
cua te » cua tu

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