Perhaps you should try some spelling variations:
cac trung » cac truong, dac trung, bac trung
cam trung » cam truong, nam trung, cao trung
nang doc » nang luc
nang doi » nang noi, hang doi, nang dong
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
cua te » cua tu
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
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: su sach y nang o hoi. hieu ve ((cam trung) or (cac trung)) va ((nang doi) OR (nang doc)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang o hoi. hieu ve ((cam trung) OR (cac trung)) va ((nang doi) OR (nang doc)) cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang o hoi. hieu ve ((cam trung) or (cac trung)) va ((nang doi) OR (nang doc)) cua te".
• Adding a wildcard symbol may retrieve word variants: su sach y nang o hoi. hieu ve ((cam trung) or (cac trung)) va ((nang doi) OR (nang doc)) cua te*.