Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su triet » su tien, ve triet
hanh ve » hanh vi, hanh va, hanh kem
va hanh » van hanh, va thanh, va danh
su viet » so viet
hieu ve » hieu va, hieu van
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
xuc va » duc va, tuc va, luc va
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: ((te sach) or (toc sach)) ky lang xa hoi. hieu ve cam xuc va hanh ve ((su triet) OR (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sach) OR (toc sach)) ky lang xa hoi. hieu ve cam xuc va hanh ve ((su triet) OR (su viet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) or (toc sach)) ky lang xa hoi. hieu ve cam xuc va hanh ve ((su triet) OR (su viet))".
• Adding a wildcard symbol may retrieve word variants: ((te sach) or (toc sach)) ky lang xa hoi. hieu ve cam xuc va hanh ve ((su triet) OR (su viet))*.