Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
va triet » va thiet, va trien, ve triet
cham duc » pham duc, cham soc, pham duy
hanh tai » thanh tai, hang tai, han tai
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
ve cham » va cham, ve chat, vu cham

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky ((tang ma) or (nang x)) hoi. hieu ve cham duc van hanh tai ((cua triet) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((tang ma) OR (nang x)) hoi. hieu ve cham duc van hanh tai ((cua triet) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((tang ma) or (nang x)) hoi. hieu ve cham duc van hanh tai ((cua triet) or (va triet))*.