Perhaps you should try some spelling variations:
hieu cua » hieu qua, dieu cua, bieu cua
dang cay » dang xay, dang ca, dang cac
cay phoi » cap phoi, tay hoi, cay cho
va hanh » van hanh, va thanh, va danh
cau luc » cau truc, cau phuc
cac luc » coc luc, cac nuoc, cac cuoc
cua tre » cua te, cuu tre, cua triet
ky dang » ky nang, ky danh
su sach » so sach, vu sach
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 cac) or (su sach)) ky dang cay phoi. hieu cua ((cac luc) OR (cau luc)) va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cac) OR (su sach)) ky dang cay phoi. hieu cua ((cac luc) OR (cau luc)) va hanh vi cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cac) or (su sach)) ky dang cay phoi. hieu cua ((cac luc) OR (cau luc)) va hanh vi cua tre*".