Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
thu sach » tu sach, thuat sach, thuoc sach
hanh van » thanh van, khanh van, hanh va
van hanh » van thanh, ban hanh, van anh
hieu va » lieu va, hieu qua
van dau » van dao, phan dau
xuc van » duc van, luc van, xuc ban
dau tre » dau tren, dau tien, cau tren
hieu ve » hieu van
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 (thu sach)) ky nang x hoi. ((hieu ve) or (hieu va)) cam xuc van hanh van dau tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thu sach)) ky nang x hoi. ((hieu ve) OR (hieu va)) cam xuc van hanh van dau tre.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (thu sach)) ky nang x hoi. ((hieu ve) or (hieu va)) cam xuc van hanh van dau tre*.