Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
va thanh » gia thanh, ban thanh, va tinh
van hanh » van thanh, ban hanh, van anh
dai cuu » dai cua, dai huu
va pham » van pham, va phat, va phap
hieu va » lieu va, hieu qua
cuu tre » cua tre, cau tren, cau treo
x hoi » xa hoi, o hoi, x ho

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) OR (doc sach)) ky nang x hoi. hieu va pham duc ((van hanh) or (va thanh)) dai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ky nang x hoi. hieu va pham duc ((van hanh) OR (va thanh)) dai cuu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) ky nang x hoi. hieu va pham duc ((van hanh) or (va thanh)) dai cuu tre*".