Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
doanh va » doan va, doanh tai, doanh cua
sach ky » sac ky, sach y, sach ty
cua tre » cua te, cua triet, dua tren
thuc va » thuc vat, thuc dan, thuc day
cuu tre » cau tren, cau treo
hieu ve » hieu va, hieu van
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
tuc va » truc va, tuc xa, duc 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: thuoc sach ky tang xa hoi. hieu ve cac ((tuc va) or (thuc va)) doanh va ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thuoc sach ky tang xa hoi. hieu ve cac ((tuc va) OR (thuc va)) doanh va ((cua tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuoc sach ky tang xa hoi. hieu ve cac ((tuc va) or (thuc va)) doanh va ((cua tre) OR (cuu tre))*".