Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
thu nang » thi nang, thu hang, thu bang
doanh va » doan va, doanh tai, doanh cua
thi cong » tai cong, thien cong
tu sach » thu sach, su sach, te sach
vu cham » va cham, vu kham, tu cham
duc van » duc va, duc tan, duc manh
ve cham » va cham, ve chat, ve chim
cua tre » cua te, cuu tre, cua triet
va cua » va chua, via cua, ca cua

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 ((thu nang) or (thi cong)) xa hoi. hieu ((ve cham) OR (vu cham)) duc van doanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((thu nang) OR (thi cong)) xa hoi. hieu ((ve cham) OR (vu cham)) duc van doanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ((thu nang) or (thi cong)) xa hoi. hieu ((ve cham) OR (vu cham)) duc van doanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ((thu nang) or (thi cong)) xa hoi. hieu ((ve cham) OR (vu cham)) duc van doanh va cua tre*.