Perhaps you should try some spelling variations:
trinh vi » trinh va, trinh ve, trinh viet
dang xay » dang van, van xay
tu sach » thu sach, su sach, te sach
cam cac » ca cac, nam cac, cam chan
tinh vi » tinh voi, tinh va, dinh vi
cac ban » cac dan, cac van, can ban
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
dang xa » lang xa, dang ha, dang va
sach 2 » sach y
ve cam » ve cham, ve cac, va cam

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 2 ((dang xa) OR (dang xay)) hoi. hieu ve cam cac ban ((tinh vi) or (trinh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach 2 ((dang xa) OR (dang xay)) hoi. hieu ve cam cac ban ((tinh vi) OR (trinh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach 2 ((dang xa) OR (dang xay)) hoi. hieu ve cam cac ban ((tinh vi) or (trinh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach 2 ((dang xa) OR (dang xay)) hoi. hieu ve cam cac ban ((tinh vi) or (trinh vi)) cua tre*.