Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
van pham » san pham, van phan, van phat
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
sach ky » sac ky, sach y, sach ty
duc van » duc va, duc tan, duc manh
nang xa » nang x, lang xa, mang xa
hanh di » hanh de, hang di, danh di
tu sach » thu sach, su sach, te sach

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 ((nang xa) OR (nang ma)) hoi. hieu van pham duc van ((hanh di) or (hanh vi)) cua triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang ma)) hoi. hieu van pham duc van ((hanh di) OR (hanh vi)) cua triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) OR (nang ma)) hoi. hieu van pham duc van ((hanh di) or (hanh vi)) cua triet*".