Perhaps you should try some spelling variations:
doc sach » hoc sach, toc sach, nuoc sach
va triet » va thiet, va trien, ve triet
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
hieu va » lieu va
sach ky » sac ky, sach y, sach ty
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh
ma hoi » mai hoi, xa hoi, ma hoa
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc sach ky sang ma hoi. ((hieu va) OR (hieu qua)) cam duc va hanh vi ((cua te) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc sach ky sang ma hoi. ((hieu va) OR (hieu qua)) cam duc va hanh vi ((cua te) OR (va triet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc sach ky sang ma hoi. ((hieu va) OR (hieu qua)) cam duc va hanh vi ((cua te) or (va triet))*".