Perhaps you should try some spelling variations:
va thanh » gia thanh, ban thanh, va tinh
tu sach » thu sach, su sach, te sach
va hanh » van hanh, va danh, ban hanh
nang xa » nang x, lang xa, nang ma
cua tre » cua te, cuu tre, cua triet
ve cac » va cac, vien cac
y nang » ky nang, ly nang, v nang
ve cau » ke cau, va cau, le cau
vi cua » vai cua, di 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 y nang xa hoi. hieu ((ve cau) OR (ve cac)) luc ((va hanh) or (va thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y nang xa hoi. hieu ((ve cau) OR (ve cac)) luc ((va hanh) OR (va thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach y nang xa hoi. hieu ((ve cau) OR (ve cac)) luc ((va hanh) or (va thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach y nang xa hoi. hieu ((ve cau) OR (ve cac)) luc ((va hanh) or (va thanh)) vi cua tre*.