Perhaps you should try some spelling variations:
trinh viet » ninh viet, trinh vat
coc truc » hoc truc, cau truc, hoc thuc
trong xa » trong xay, trong ca, trong xu
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
tinh vi » trinh vi, tinh voi, tinh va
van coc » van hoc, van loc, van co
truc va » thuc va, thuc vat, trung va
sach ty » sach y, sach tu, sach thu
tang ma » mang may, tang van
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: vu sach ty ((tang ma) or (trong xa)) hoi. hieu van coc truc va ((tinh vi) or (trinh viet)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty ((tang ma) OR (trong xa)) hoi. hieu van coc truc va ((tinh vi) OR (trinh viet)) cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach ty ((tang ma) or (trong xa)) hoi. hieu van coc truc va ((tinh vi) or (trinh viet)) cua tre*.