Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
hieu ve » hieu va, hieu van
anh dai » vanh dai, anh bai, anh dat
vuc van » duc van, luc van, thuc van
xuc van » duc van, luc van, xuc ban
tu cach » tu cac
ve cam » ve cham, ve cac, va cam
nang o » nang co, nang ho, nang ro
v nang » va nang, vu nang, van nang
cua te » cua tu
o hoi » co hoi, o hoc, o hai

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (toc sach)) v nang o hoi. hieu ve cam ((xuc van) OR (vuc van)) anh dai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (toc sach)) v nang o hoi. hieu ve cam ((xuc van) OR (vuc van)) anh dai cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu cach) or (toc sach)) v nang o hoi. hieu ve cam ((xuc van) OR (vuc van)) anh dai cua te".
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (toc sach)) v nang o hoi. hieu ve cam ((xuc van) OR (vuc van)) anh dai cua te*.