Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu ve » hieu va, hieu van
luc ban » cuc ban, luc bat, luc van
duc ban » duc tan, duc van, dua ban
ve cam » ve cham, ve cac, va cam
vi cua » vai cua, di cua
cua te » cua tu
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: ((te sach) OR (toc sach)) ky nang x hoi. hieu ve cam ((luc ban) or (duc ban)) hanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky nang x hoi. hieu ve cam ((luc ban) OR (duc ban)) hanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ky nang x hoi. hieu ve cam ((luc ban) or (duc ban)) hanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ky nang x hoi. hieu ve cam ((luc ban) or (duc ban)) hanh vi cua te*.