Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
danh di » danh du, xanh di, danh dien
va danh » va dinh, va dan, va hanh
truc va » thuc va, thuc vat, trung va
van hac » van hoc, van ha, van hai
tu sach » thu sach, su sach, te sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
dan bac » dan ba, van bac, dong bac
di su » doi su, ki su, da 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 (nang ma)) hoi. hieu ((dan bac) or (van hac)) truc va danh di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang ma)) hoi. hieu ((dan bac) OR (van hac)) truc va danh di su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) OR (nang ma)) hoi. hieu ((dan bac) or (van hac)) truc va danh di su triet".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) OR (nang ma)) hoi. hieu ((dan bac) or (van hac)) truc va danh di su triet*.