Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
su sach » so sach, vu sach
cua tre » cua te, cuu tre, cua triet
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
dang ha » dong ha, dung ha, lang ha
dang xa » dang xay, lang xa, dang va
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach thu ((dang xa) OR (dang ha)) hoi. hieu ve pham duc van hanh vai ((cua tre) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((dang xa) OR (dang ha)) hoi. hieu ve pham duc van hanh vai ((cua tre) OR (cua tu)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach thu ((dang xa) OR (dang ha)) hoi. hieu ve pham duc van hanh vai ((cua tre) or (cua tu))".
• Adding a wildcard symbol may retrieve word variants: su sach thu ((dang xa) OR (dang ha)) hoi. hieu ve pham duc van hanh vai ((cua tre) or (cua tu))*.