Perhaps you should try some spelling variations:
cham doc » cham soc, chat doc, chau doc
nang xa » nang x, nang ma, mang xa
lang xa » lang ha, dang xay, lang van
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
va hanh » van hanh, va thanh, va danh
te sac » te sach, te cac, te san
sac ky » cac ky, sai ky
doc va » duoc va, hoc va, duc va
cua tu » cua tuc, cua su, cua te
cua cu » cua chu, cua cau, cua su

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 xa) or (lang xa)) hoi. hieu ve cham doc va hanh vi ((cua tu) or (cua cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sac ky ((nang xa) OR (lang xa)) hoi. hieu ve cham doc va hanh vi ((cua tu) OR (cua cu)).
• Adding a wildcard symbol may retrieve word variants: te sac ky ((nang xa) or (lang xa)) hoi. hieu ve cham doc va hanh vi ((cua tu) or (cua cu))*.