Perhaps you should try some spelling variations:
nang xa » lang xa, nang ma, mang xa
sach ky » sach y, sach ty, sach kem
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
ve cac » va cac, vien cac
cac lo » cac lop, cac co, cac bo
va cua » va chua, via cua, ca cua
lo va » lo van, lao va, ly va

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ky) or (sac ky)) ((nang xa) OR (nang x)) hoi. hieu ve cac lo va hanh va cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ky) OR (sac ky)) ((nang xa) OR (nang x)) hoi. hieu ve cac lo va hanh va cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ky) or (sac ky)) ((nang xa) OR (nang x)) hoi. hieu ve cac lo va hanh va cua tre".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ky) or (sac ky)) ((nang xa) OR (nang x)) hoi. hieu ve cac lo va hanh va cua tre*.