Perhaps you should try some spelling variations:
nang doc » nang luc
van hanh » van thanh, ban hanh, van ban
su sach » so sach, vu sach
tai cuu » tai cuc, tai buu, tai cua
van anh » van thanh, tuan anh, van minh
cuu tre » cua tre, cau tren, cau treo
cac xuc » cam xuc, cac nuoc, chat xuc
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
nang o » nang co, nang ho, nang ro
ve cac » va cac, vien cac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang o) OR (nang doc)) hoi. hieu ve cac xuc ((van hanh) OR (van anh)) tai cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((nang o) or (nang doc)) hoi. hieu ve cac xuc ((van hanh) OR (van anh)) tai cuu tre~".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang o) or (nang doc)) hoi. hieu ve cac xuc ((van hanh) OR (van anh)) tai cuu tre*.