Perhaps you should try some spelling variations:
doanh va » doan va, doanh tai, doanh cua
va doanh » van doanh, vay doanh, va danh
tu sach » thu sach, su sach, te sach
cua tre » cua te, cuu tre, cua triet
ky dang » ky nang, ky danh
ky lang » ky nang, ky tang, tay lang
ve cam » ve cham, ve cac, ve cai
va cam » va cham, va cac, va cao
luc va » duc va, tuc va, loc va
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 ((ky lang) or (ky dang)) xa hoi. hieu ((ve cam) or (va cam)) luc va doanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((ky lang) OR (ky dang)) xa hoi. hieu ((ve cam) OR (va cam)) luc va doanh va cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ((ky lang) or (ky dang)) xa hoi. hieu ((ve cam) or (va cam)) luc va doanh va cua tre*.