Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
su sach » so sach, vu sach
nang xa » lang xa, nang ma, mang xa
va hanh » van hanh, va thanh, va danh
so viet » hoc viet
vi so » vi soi, vi mo, va so

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 thu ((nang xa) or (nang x)) hoi. hieu van pham duc va hanh vi so viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((nang xa) OR (nang x)) hoi. hieu van pham duc va hanh vi so viet.
• Adding a wildcard symbol may retrieve word variants: su sach thu ((nang xa) or (nang x)) hoi. hieu van pham duc va hanh vi so viet*.