Perhaps you should try some spelling variations:
trinh ve » trinh he, trinh va, trinh viet
trinh vi » trinh va, trinh viet, trinh van
tu sach » thu sach, su sach, te sach
cac ban » cac dan, cac van, can ban
vu cham » va cham, vu kham, tu cham
sach ky » sac ky, sach y, sach ty
ve chat » va chat, van chat
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet

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