Perhaps you should try some spelling variations:
trinh viet » trinh vat
ninh viet » sinh vien, anh viet
trinh vi » trinh va, trinh ve, trinh van
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
hieu va » lieu va, hieu qua
dang xa » dang xay, lang xa, dang ha
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
va coc » va cuoc, va cac, va hoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky dang xa hoi. hieu va coc luc va ((trinh vi) or (((trinh viet) OR (ninh viet)))) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky dang xa hoi. hieu va coc luc va ((trinh vi) OR (((trinh viet) OR (ninh viet)))) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky dang xa hoi. hieu va coc luc va ((trinh vi) or (((trinh viet) OR (ninh viet)))) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ky dang xa hoi. hieu va coc luc va ((trinh vi) or (((trinh viet) OR (ninh viet)))) cua tre*.