Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
va pham » van pham, va phat, va phap
duc ban » duc tan, dua ban, duc man
duc van » duc va, duc tan, duc manh
hanh va » hang va, hanh vi

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 ty ((nang xa) or (nang ma)) hoi. lieu va pham ((duc ban) OR (duc van)) hanh va su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang ma)) hoi. lieu va pham ((duc ban) OR (duc van)) hanh va su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty ((nang xa) or (nang ma)) hoi. lieu va pham ((duc ban) OR (duc van)) hanh va su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang ma)) hoi. lieu va pham ((duc ban) OR (duc van)) hanh va su triet*.