Perhaps you should try some spelling variations:
hieu hien » bieu hien, dieu hien, chieu chien
tang hanh » tang thanh, dang hanh, nang hanh
hoc sach » hoc sinh, hoc cac, hoc anh
cac thoi » cac toi, cac tro
sach ky » sac ky, sach y, sach ty
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
cac thu » cach thuc
cua tre » cua te, cuu tre, cua triet
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: hoc sach ky dang xa hoi. hieu hien ((((cac thoi) or (cac thu))) or (cac hop)) tang hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky dang xa hoi. hieu hien ((((cac thoi) OR (cac thu))) OR (cac hop)) tang hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: hoc sach ky dang xa hoi. hieu hien ((((cac thoi) or (cac thu))) or (cac hop)) tang hanh vi cua tre*.