Perhaps you should try some spelling variations:
nuoc sach » nguoi sach, cuoc cach, cuon sach
doanh van » doan van, doanh va, doanh ban
van doanh » toan doanh, van dong, van thanh
hoc sach » hoc sinh, hoc cac, hoc anh
cua tre » cuu tre, cua triet, dua tren
ky tang » ky nang, ky dang, kho tang
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
tuc van » thuc van, truc van, tuc va
ve cac » va cac, vien cac
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((nuoc sach) or (hoc sach)) ky tang ma hoa. hieu ve cac tuc van doanh van ((cua tre) OR (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((nuoc sach) OR (hoc sach)) ky tang ma hoa. hieu ve cac tuc van doanh van ((cua tre) OR (cua te))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((nuoc sach) or (hoc sach)) ky tang ma hoa. hieu ve cac tuc van doanh van ((cua tre) OR (cua te))*".