Perhaps you should try some spelling variations:
thieu nien » thien nhien
nien cac » vien cac, dien cac, bien cac
su triet » su viet, su tien, ve triet
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
toc van » tac van, oc van, toc va
hoc van » hoc dan, hoc va, hoc vat
y nang » ky nang, ly nang, v nang
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach y nang xa hoi. thieu nien cac ((((toc van) OR (hoc van))) or (toc san)) hanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach y nang xa hoi. thieu nien cac ((((toc van) OR (hoc van))) OR (toc san)) hanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach y nang xa hoi. thieu nien cac ((((toc van) OR (hoc van))) or (toc san)) hanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: su sach y nang xa hoi. thieu nien cac ((((toc van) OR (hoc van))) or (toc san)) hanh vi su triet*.