Perhaps you should try some spelling variations:
cau triet » cau trieu, su triet, cua triet
gia hanh » gia thanh, giao hanh, gia anh
tu sach » thu sach, su sach, te sach
duc gia » quoc gia
cac duc » cac du, cao duc, cac dac
hieu ve » hieu va, hieu van
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
ve cac » va cac, vien cac

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 ve cac duc gia hanh vi ((cau triet) or (cau thi))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang xa) OR (nang ma)) hoi. hieu ve cac duc gia hanh vi ((cau triet) OR (cau thi)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ky ((nang xa) OR (nang ma)) hoi. hieu ve cac duc gia hanh vi ((cau triet) or (cau thi))".
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang xa) OR (nang ma)) hoi. hieu ve cac duc gia hanh vi ((cau triet) or (cau thi))*.