Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
thu dang » thu hang, thu bang, thu dong
tu sach » thu sach, su sach, te sach
dang xa » dang xay, lang xa, dang ha
hieu su » hieu sau, tieu su, hieu so
su kham » su pham, vu kham, so kham
hoc van » hoc dan, hoc va, hoc phan
hoc vat » hoc va, hoc viet, thuc vat
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: tu sach thu dang xa hoi. hieu su kham ((hoc van) or (hoc vat)) hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu dang xa hoi. hieu su kham ((hoc van) OR (hoc vat)) hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thu dang xa hoi. hieu su kham ((hoc van) or (hoc vat)) hanh vi cua tre*.