Perhaps you should try some spelling variations:
tham thuc » nham thuc, pham thuc, tam thuc
tham luc » than luc, tham nuoc, nhan luc
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
dang xa » dang xay, lang xa, dang ha
hieu va » lieu va
ky dang » ky nang, ky danh
sac ky » cac ky, sai ky
vi cua » vai cua, di cua
te sac » te sach, te cac, te san

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 dang xa hoi. ((hieu va) or (hieu qua)) ((tham luc) OR (tham thuc)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky dang xa hoi. ((hieu va) OR (hieu qua)) ((tham luc) OR (tham thuc)) va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sac ky dang xa hoi. ((hieu va) or (hieu qua)) ((tham luc) OR (tham thuc)) va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te sac ky dang xa hoi. ((hieu va) or (hieu qua)) ((tham luc) OR (tham thuc)) va hanh vi cua tre*.