Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
doc sach » hoc sach, nuoc sach, dac sac
hang doi » hang di, hang loi, huong doi
tu nang » tru nang, tu nong, tu nano
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va cham » va chat, va tham
cham tu » pham tu, cam tu, chai tu
va hang » van hang, va nang, va lang
doi cuu » doi cua, doi cuoc
cuu tre » cua tre, cau tren, cau treo

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)) tu nang xa hoi. hieu va cham tu va hang doi cuu tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (doc sach)) tu nang xa hoi. hieu va cham tu va hang doi cuu tre".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (doc sach)) tu nang xa hoi. hieu va cham tu va hang doi cuu tre*.