Perhaps you should try some spelling variations:
su sach » so sach, vu sach
sach ky » sac ky, sach y, sach ty
nang xa » lang xa, nang ma, mang xa
hieu va » lieu va, hieu qua
va hanh » van hanh, va thanh, va danh
va cam » va cham, va cac, va cao
va han » va phan, van han, va hang
thiet » thieu

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 ky ((nang xa) or (nang x)) hoi. hieu va cam xuc ((va han) or (va hanh)) tri va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((nang xa) OR (nang x)) hoi. hieu va cam xuc ((va han) OR (va hanh)) tri va thiet.
• Adding a wildcard symbol may retrieve word variants: su sach ky ((nang xa) or (nang x)) hoi. hieu va cam xuc ((va han) or (va hanh)) tri va thiet*.