Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
cau luc » cau truc, cau phuc
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
cua tre » cua te, cuu tre, cua triet
ve cau » ke cau, va cau, ve cac
de cua » le cua, te cua, dieu cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky ((nang ma) OR (sang ma)) hoi. hieu ve cau luc ((ban hanh) or (van minh)) de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky ((nang ma) OR (sang ma)) hoi. hieu ve cau luc ((ban hanh) OR (van minh)) de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky ((nang ma) OR (sang ma)) hoi. hieu ve cau luc ((ban hanh) or (van minh)) de cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach ky ((nang ma) OR (sang ma)) hoi. hieu ve cau luc ((ban hanh) or (van minh)) de cua tre*.