Perhaps you should try some spelling variations:
toc nguoi » con nguoi
dao hanh » dao thanh, dang hanh, ban hanh
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
hanh di » hanh vi, hanh de, hang di
su sac » su sach, su cac, su xac
cua tu » cua tuc, cua su, cua cu
sac ky » cac ky, sai ky
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 sac ky nang o hoi. hieu ve ((thuc nguoi) OR (toc nguoi)) dao hanh di ((cua tre) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang o hoi. hieu ve ((thuc nguoi) OR (toc nguoi)) dao hanh di ((cua tre) OR (cua tu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang o hoi. hieu ve ((thuc nguoi) OR (toc nguoi)) dao hanh di ((cua tre) or (cua tu))*".