Perhaps you should try some spelling variations:
va triet » va thiet, va trien, ve triet
cua tre » cua te, cuu tre, cua triet
va hanh » van hanh, va thanh, va danh
sach ky » sac ky, sach y, sach ty
tu sach » thu sach, su sach, te sach
lang ha » long ha
hieu ve » hieu va, hieu van
ky lang » ky nang, ky dang, ky tang
ha hoi » hoa hoi, ha noi, xa hoi
cap y » cap 2, cap 1, cap 5

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 lang ha hoi. hieu ve ((cap y) or (cac ky)) va hanh vi ((cua tre) or (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky lang ha hoi. hieu ve ((cap y) OR (cac ky)) va hanh vi ((cua tre) OR (va triet)).
• Adding a wildcard symbol may retrieve word variants: tu sach ky lang ha hoi. hieu ve ((cap y) or (cac ky)) va hanh vi ((cua tre) or (va triet))*.