Perhaps you should try some spelling variations:
thanh son » thanh san, thanh cong, thanh toan
so sach » so sanh, bo sach, co sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va chay » va chat, va cham, va cay
dua ban » cua ban, qua ban, mua ban
son cua » song cua, con cua, san cua
cua tre » cua te, cuu tre, cua triet
y nang » ky nang, ly nang, v nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y nang xa hoi. hieu va chay ((dua ban) OR (dia ban)) thanh son cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y nang xa hoi. hieu va chay ((dua ban) OR (dia ban)) thanh son cua tre".
• Adding a wildcard symbol may retrieve word variants: so sach y nang xa hoi. hieu va chay ((dua ban) OR (dia ban)) thanh son cua tre*.