Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
doanh van » doan van, doanh va, doanh ban
thu bang » thu ban, thu hang, chu bang
bang xa » lang xa, bang va, mang xa
hieu va » lieu va, hieu qua
van cua » vang cua, ban cua, dan cua
va cam » va cham, va cac, va cao
luc va » duc va, tuc va, loc va
xuc va » duc va, tuc va, xac va
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: ((thu hoach) or (thuoc sach)) thu bang xa hoi. hieu va cam ((xuc va) OR (luc va)) doanh van cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu hoach) OR (thuoc sach)) thu bang xa hoi. hieu va cam ((xuc va) OR (luc va)) doanh van cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((thu hoach) or (thuoc sach)) thu bang xa hoi. hieu va cam ((xuc va) OR (luc va)) doanh van cua te".
• Adding a wildcard symbol may retrieve word variants: ((thu hoach) or (thuoc sach)) thu bang xa hoi. hieu va cam ((xuc va) OR (luc va)) doanh van cua te*.