Perhaps you should try some spelling variations:
cham duc » pham duc, cham soc, pham duy
so sach » so sanh, bo sach, co sach
nang xa » lang xa, nang ma, mang xa
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
van han » van hanh, van phan, van nhan
thai va » thai van
va hieu » van hieu, va dieu, va hien
va han » va phan, va hanh, va hang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach y ((nang xa) or (nang x)) hoi. hieu ve cham duc ((va han) OR (van han)) thai va hieu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach y ((nang xa) OR (nang x)) hoi. hieu ve cham duc ((va han) OR (van han)) thai va hieu.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach y ((nang xa) or (nang x)) hoi. hieu ve cham duc ((va han) OR (van han)) thai va hieu".
• Adding a wildcard symbol may retrieve word variants: so sach y ((nang xa) or (nang x)) hoi. hieu ve cham duc ((va han) OR (van han)) thai va hieu*.