Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
nang xa » nang x, lang xa, nang ma
tang ma » mang may, tang van
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
co duc » co duoc, cao duc, do duc
va co » vo co
vi va » vai va, vu va, bi va

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

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