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