Perhaps you should try some spelling variations:
sach thue » sach thieu, sach tham, cach thuc
sach thu » sach thieu, sach tham, cach thuc
qua pham » quan pham, quy pham, qua cham
ban hanh » ban hang
hanh vai » hanh vi, hanh va, hanh tai
dang xa » dang xay, lang xa, dang ha
duc ban » duc tan, duc van, dua ban
cua tre » cuu tre, cua triet, dua tren
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: vu ((sach thu) OR (sach thue)) dang xa hoi. hieu qua pham duc ban hanh vai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach thu) OR (sach thue)) dang xa hoi. hieu qua pham duc ban hanh vai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach thu) OR (sach thue)) dang xa hoi. hieu qua pham duc ban hanh vai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: vu ((sach thu) OR (sach thue)) dang xa hoi. hieu qua pham duc ban hanh vai ((cua tre) or (cua te))*.