Perhaps you should try some spelling variations:
trinh vi » trinh va, trinh ve, trinh viet
su sach » so sach, vu sach
hieu va » lieu va, hieu qua
tinh vi » tinh voi, tinh va, dinh vi
cua tre » cua te, cuu tre, cua triet
y dang » ky dang, 2 dang, b dang
_ dang » _ dan, 2 dang, _ danh
va coc » va cuoc, va cac, va hoc
luc va » duc va, tuc va, loc va

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