Perhaps you should try some spelling variations:
thu sac » thu sach, thu san, thu xac
hieu va » lieu va, hieu qua
duc ban » duc tan, duc van, duc man
dua ban » dia ban, cua ban, qua ban
cuc tre » cua tre, cuu tre, cuc thue
duc tre » duoc tren, duc tien
sac ky » cac ky, sai ky
va gia » va giai
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: thu sac ky nang x hoi. hieu va gia ((duc ban) OR (dua ban)) thanh san ((cuc tre) or (duc tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sac ky nang x hoi. hieu va gia ((duc ban) OR (dua ban)) thanh san ((cuc tre) OR (duc tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sac ky nang x hoi. hieu va gia ((duc ban) OR (dua ban)) thanh san ((cuc tre) or (duc tre))*".