Perhaps you should try some spelling variations:
sach cam » sach cap, mach cam, sach tham
qua pham » quan pham, quy pham, qua cham
su triet » su tien, ve triet
su sach » so sach, vu sach
nang ma » sang ma, nang cao, mang may
tang ma » mang may, tang van
va dinh » van dinh, va kinh, va tinh
dinh le » dinh ve, dinh ly, dinh ket
su viet » so viet

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 cam ((nang ma) OR (tang ma)) hoi. hieu qua pham duc va dinh le ((su triet) OR (su viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach cam ((nang ma) or (tang ma)) hoi. hieu qua pham duc va dinh le ((su triet) OR (su viet))~".
• Adding a wildcard symbol may retrieve word variants: su sach cam ((nang ma) or (tang ma)) hoi. hieu qua pham duc va dinh le ((su triet) OR (su viet))*.