Perhaps you should try some spelling variations:
vien cac » vien bach, vien dai, vien da
cua tre » cua te, cuu tre, cua triet
nang xa » nang x, lang xa, mang xa
va hanh » van hanh, va thanh, va danh
nang ma » tang ma, sang ma, nang cao
vi cua » vai cua, di cua
luc va » duc va, tuc va, loc va
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
ve cac » va cac

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

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