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