Perhaps you should try some spelling variations:
cua triet » cua viet, su triet
tieu hieu » tieu bieu, thien hieu, tieu khien
toc sach » hoc sach, doc sach, thuoc sach
hieu cac » hieu luc, hieu va, hieu van
va triet » va thiet, va trien, ve triet
sach ky » sac ky, sach y, sach ty
hanh va » hang va, hanh vi
nang xa » nang x, lang xa, nang ma
xac va » tac va, ac va, bac va
tuc va » thuc va, truc va, tuc xa

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 nang xa hoi. tieu hieu cac ((xac va) or (tuc va)) hanh va ((cua triet) OR (va triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky nang xa hoi. tieu hieu cac ((xac va) OR (tuc va)) hanh va ((cua triet) OR (va triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach ky nang xa hoi. tieu hieu cac ((xac va) or (tuc va)) hanh va ((cua triet) OR (va triet))".
• Adding a wildcard symbol may retrieve word variants: toc sach ky nang xa hoi. tieu hieu cac ((xac va) or (tuc va)) hanh va ((cua triet) OR (va triet))*.