Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
hieu vu » hieu va, hieu ve, hieu su
vu cham » va cham, vu kham, tu cham
va danh » va dinh, va dan, va hanh
danh vi » hanh vi, dinh vi, danh di
cua tre » cua te, cuu tre, cua triet
ca tren » cau tren, cu tren, la tren
te sac » te sach, te cac, te san
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: te sac ky nang o hoi. hieu vu cham duc va danh vi ((cua tre) or (ca tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky nang o hoi. hieu vu cham duc va danh vi ((cua tre) OR (ca tren)).
• Adding a wildcard symbol may retrieve word variants: te sac ky nang o hoi. hieu vu cham duc va danh vi ((cua tre) or (ca tren))*.