Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
ban hanh » ban hang
va triet » va thiet, va trien, ve triet
cam duc » cam xuc, cao duc, pham duc
sang ma » tang ma, nang ma, sang tao
duc ban » duc tan, duc van, dua ban
hieu va » hieu qua
sach v » sach va, sach y, sach 2
kem va » kiem va, kiem van

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach v ((nang cao) or (sang ma)) hoi. ((hieu va) or (lieu va)) cam duc ban hanh kem va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach v ((nang cao) OR (sang ma)) hoi. ((hieu va) OR (lieu va)) cam duc ban hanh kem va triet.
• Adding a wildcard symbol may retrieve word variants: toc sach v ((nang cao) or (sang ma)) hoi. ((hieu va) or (lieu va)) cam duc ban hanh kem va triet*.