Perhaps you should try some spelling variations:
qua cham » qua hai, qua cac, va cham
sach cam » sach cap, mach cam, sach tham
su triet » su tien, ve triet
cham duc » pham duc, cham soc, pham duy
tinh ly » trinh ly, sinh ly, dinh ly
va tinh » may tinh
su sach » so sach, vu sach
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
su viet » so viet

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 cam ((nang ma) or (tang ma)) hoi. hieu qua cham duc va tinh ly ((su triet) OR (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach cam ((nang ma) OR (tang ma)) hoi. hieu qua cham duc va tinh ly ((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 cham duc va tinh ly ((su triet) OR (su viet))*".