Perhaps you should try some spelling variations:
su sach » so sach, vu sach
cao luc » bao luc, cao duc, cao suc
nang xa » lang xa, nang ma, mang xa
va phan » van phan, va phat, va phap
hieu va » lieu va, hieu qua
sach ty » sach y, sach tu, sach thu
va han » van han, va hanh, va hang
va cao » va cac, va co, va dao
tai va » thai va, mai va, tri va
thiet » thieu

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: su sach ty ((nang xa) OR (nang x)) hoi. hieu va cao luc ((va han) OR (va phan)) tai va thiet~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang xa) or (nang x)) hoi. hieu va cao luc ((va han) OR (va phan)) tai va thiet~".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (nang x)) hoi. hieu va cao luc ((va han) OR (va phan)) tai va thiet*.