Perhaps you should try some spelling variations:
sach thien » sach thieu, sach tien, cach thien
thien bang » khien bang, thien ban, thien dang
tu sach » thu sach, su sach, te sach
bang xa » lang xa, bang va, mang xa
hieu ve » hieu va, hieu van
duc van » duc va, duc manh, duc phan
cuu tre » cua tre, cau tren, cau treo
ve cam » ve cham, ve cac, va cam
cua te » cua tu

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 thien bang xa hoi. hieu ve cam ((duc van) or (duc tan)) hanh vi ((cua te) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thien bang xa hoi. hieu ve cam ((duc van) OR (duc tan)) hanh vi ((cua te) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu sach thien bang xa hoi. hieu ve cam ((duc van) or (duc tan)) hanh vi ((cua te) or (cuu tre))*.