Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
thu sach » tu sach, thuat sach, thuoc sach
va doanh » vay doanh, va danh, hoa doanh
cam luc » cam xuc, cau luc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
va cua » va chua, via cua, ca cua
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach ((ky lang) or (ky dang)) xa hoi. hieu ve cam luc ((va doanh) OR (van doanh)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ((ky lang) OR (ky dang)) xa hoi. hieu ve cam luc ((va doanh) OR (van doanh)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach ((ky lang) or (ky dang)) xa hoi. hieu ve cam luc ((va doanh) OR (van doanh)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach ((ky lang) or (ky dang)) xa hoi. hieu ve cam luc ((va doanh) OR (van doanh)) va cua tre*.