Perhaps you should try some spelling variations:
cua triet » cua viet, va triet
hoc sach » hoc sinh, hoc cac, hoc anh
ban hanh » ban hang
than duc » tran duc, phan duc, than doc
su triet » su viet, su tien, ve triet
va than » va thanh, van than, va phan
sach ky » sac ky, sach y, sach ty
duc ban » duc tan, duc van, dua ban
hanh di » hanh vi, hanh de, hang di
o hoc » co hoc, mo hoc, so hoc

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc sach ky nang ((o hoc) or (xa hoi)). lieu va than duc ban hanh di ((cua triet) OR (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ky nang ((o hoc) OR (xa hoi)). lieu va than duc ban hanh di ((cua triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ky nang ((o hoc) or (xa hoi)). lieu va than duc ban hanh di ((cua triet) OR (su triet))".
• Adding a wildcard symbol may retrieve word variants: hoc sach ky nang ((o hoc) or (xa hoi)). lieu va than duc ban hanh di ((cua triet) OR (su triet))*.