Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
cau tren » cu tren, dau tren, ca tren
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
tu sach » thu sach, su sach, te sach
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 ty ((nang xa) or (nang ma)) hoi. hieu ve cac duc va hanh vi ((cau tren) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty ((nang xa) OR (nang ma)) hoi. hieu ve cac duc va hanh vi ((cau tren) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ty ((nang xa) or (nang ma)) hoi. hieu ve cac duc va hanh vi ((cau tren) or (cua triet))*.