Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
va trien » va truyen, va thiet, va tuyen
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
qua cam » qua cham, qua cac, qua ca
cam duc » cam xuc, cao duc, pham duc
va hanh » van hanh, va thanh, va danh

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

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