Perhaps you should try some spelling variations:
dinh vai » dinh van, dinh vi, dinh va
vu sach » vu bach, su sach, vu khach
vai cua » dai cua, hai cua, lai cua
sach ty » sach y, sach tu, sach thu
qua cac » cua cac
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cua tre » cua te, cuu tre, cua triet
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa

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 ((nang xa) or (nang ma)) hoi. hieu qua cac ((xuc va) OR (tuc va)) dinh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty ((nang xa) OR (nang ma)) hoi. hieu qua cac ((xuc va) OR (tuc va)) dinh vai cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty ((nang xa) or (nang ma)) hoi. hieu qua cac ((xuc va) OR (tuc va)) dinh vai cua tre*".