Perhaps you should try some spelling variations:
van doanh » toan doanh, van dong, van thanh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang co » nang cao, nang doc, nang noi
nang ho » nang hoc, tang ho, nang cao
hieu ve » hieu va, hieu van
cac xuc » cam xuc, cac nuoc, chat xuc
xuc van » duc van, luc van, vuc van
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
nang o » nang ro, nang x, lang o
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky ((((nang o) OR (nang co))) or (nang ho)) hoi. hieu ve cac xuc van doanh tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((((nang o) OR (nang co))) OR (nang ho)) hoi. hieu ve cac xuc van doanh tai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((((nang o) OR (nang co))) or (nang ho)) hoi. hieu ve cac xuc van doanh tai cua tre*".