Perhaps you should try some spelling variations:
trinh viet » ninh viet, trinh vat
trinh vi » trinh va, trinh ve, trinh van
cuc ban » cua ban, cac ban, cuu ban
tu sach » thu sach, su sach, te sach
tu cham » toc cham, thi cham
ve cham » va cham, ve chat, vu cham
dang xa » dang xay, lang xa, dang ha
cua tre » cua te, cuu tre, cua triet
y dang » ky dang, 2 dang, _ dang

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