Perhaps you should try some spelling variations:
doanh luan » doanh nhan
tu sach » thu sach, su sach, te sach
cac xuc » cam xuc, cac nuoc, chat xuc
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
sang ma » tang ma, sang tao, mang may
nang ma » tang ma, nang cao, mang may
xuc va » duc va, tuc va, luc va
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 ((nang ma) OR (sang ma)) hoi. hieu ve cac xuc va ((doanh cua) or (doanh luan)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (sang ma)) hoi. hieu ve cac xuc va ((doanh cua) OR (doanh luan)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang ma) OR (sang ma)) hoi. hieu ve cac xuc va ((doanh cua) or (doanh luan)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) OR (sang ma)) hoi. hieu ve cac xuc va ((doanh cua) or (doanh luan)) cua tre*.