Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
cay phoi » cap phoi, tay hoi, cay cho
ve triet » va trien
van hanh » van thanh, ban hanh, van anh
su triet » su viet, su tien
xay hoi » xa hoi, tay hoi, gay thoi
sach ky » sac ky, sach y, sach ty
xuc van » duc van, luc van, vuc van
hanh ve » hanh vi, hanh va, hanh kem
ky dang » ky nang, ky danh
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach ky dang ((xay hoi) OR (cay phoi)). hieu ve cam xuc van hanh ve ((ve triet) or (su triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky dang ((xay hoi) OR (cay phoi)). hieu ve cam xuc van hanh ve ((ve triet) OR (su triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky dang ((xay hoi) OR (cay phoi)). hieu ve cam xuc van hanh ve ((ve triet) or (su triet))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky dang ((xay hoi) OR (cay phoi)). hieu ve cam xuc van hanh ve ((ve triet) or (su triet))*.