Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
van hanh » van thanh, ban hanh, van anh
bao suc » bao luc, cao suc, bao thuc
cuu tre » cua tre, cau tren, cau treo
hieu ve » hieu va, hieu van
nang ma » tang ma, sang ma, nang cao
ma hoi » mai hoi, xa hoi, ma hoa
di cuu » di cau, di cua, dinh cuu
ve bao » te bao, va bao

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

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