Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hanh tai » thanh tai, hang tai, han tai
nang noi » nang doc
ban hanh » ban hang
cao xuc » cam xuc, cao duc, cao suc
nang co » nang cao, nang doc, nang hoc
tai cua » thai cua, tai cuc, tri cua
hieu va » lieu va
xuc ban » duc ban, cuc ban, quoc ban
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: toc sach y ((nang co) or (nang noi)) hoi. ((hieu va) OR (hieu qua)) cao xuc ban hanh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y ((nang co) OR (nang noi)) hoi. ((hieu va) OR (hieu qua)) cao xuc ban hanh tai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y ((nang co) or (nang noi)) hoi. ((hieu va) OR (hieu qua)) cao xuc ban hanh tai cua te".
• Adding a wildcard symbol may retrieve word variants: toc sach y ((nang co) or (nang noi)) hoi. ((hieu va) OR (hieu qua)) cao xuc ban hanh tai cua te*.