Perhaps you should try some spelling variations:
doanh qua » doanh quan, doanh cua, danh qua
qua cua » quan cua, quang cua, qua quan
sach ky » sac ky, sach y, sach kem
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach tu, sach thu
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
ve cac » va cac, vien cac

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) OR (sach ty)) nang xa hoi. hieu ve cac ((xuc va) or (tuc va)) doanh qua cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu ve cac ((xuc va) OR (tuc va)) doanh qua cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach ky) OR (sach ty)) nang xa hoi. hieu ve cac ((xuc va) or (tuc va)) doanh qua cua tre".
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) OR (sach ty)) nang xa hoi. hieu ve cac ((xuc va) or (tuc va)) doanh qua cua tre*.