Perhaps you should try some spelling variations:
nang cau » nang cao, hang cau, nang dau
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
va danh » va dinh, va hanh, dia danh
ve chat » va chat, van chat
ty nang » ky nang, ty xang, ty hang
cua tre » cua te, cuu tre, cua triet
ve cai » va cai, ve cac, ve tai
va dan » ca dan, va dao, va dau
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 ty nang cau hoi. hieu ((ve cai) or (ve chat)) ly ((va danh) OR (va dan)) va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty nang cau hoi. hieu ((ve cai) OR (ve chat)) ly ((va danh) OR (va dan)) va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty nang cau hoi. hieu ((ve cai) or (ve chat)) ly ((va danh) OR (va dan)) va cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ty nang cau hoi. hieu ((ve cai) or (ve chat)) ly ((va danh) OR (va dan)) va cua tre*.