Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
va hanh » va thanh, va danh, ban hanh
tai cua » thai cua, tai cuc, tri cua
cua tre » cua te, cuu tre, cua triet
va nam » van nam, va nay

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 cau hoi. lieu ((va nam) OR (ha nam)) luc ((va hanh) or (van hanh)) tai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky nang cau hoi. lieu ((va nam) OR (ha nam)) luc ((va hanh) OR (van hanh)) tai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky nang cau hoi. lieu ((va nam) OR (ha nam)) luc ((va hanh) or (van hanh)) tai cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky nang cau hoi. lieu ((va nam) OR (ha nam)) luc ((va hanh) or (van hanh)) tai cua tre*.