Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
hanh vai » hanh vi, hanh va, hanh tai
van hanh » van thanh, ban hanh, van anh
va hanh » va thanh, va danh, ban hanh
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
lang xa » lang ha, dang xay, lang van
nang xa » nang x, nang ma, mang xa
van hai » van ha, van chat, van phan
luc va » duc va, tuc va, loc va
vai su » va su, van su, lai su

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