Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
dua tren » dung tren
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
van cau » van dau, van hau, van chat
xuc ban » duc ban, quoc ban, xuat ban
sach ky » sac ky, sach y, sach ty
cuc ban » cua ban, cac ban, cuu ban
hanh va » hang va, hanh vi
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 sach ky nang x hoi. hieu van cau ((xuc ban) or (cuc ban)) hanh va ((dua tren) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang x hoi. hieu van cau ((xuc ban) OR (cuc ban)) hanh va ((dua tren) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang x hoi. hieu van cau ((xuc ban) or (cuc ban)) hanh va ((dua tren) or (cau tren))*.