Perhaps you should try some spelling variations:
thieu nien » thien nhien
ve triet » va trien
su triet » su viet, su tien
van hanh » van thanh, ban hanh, van anh
nuoc van » nuoc va, nuoc san, luoc van
cac nuoc » cap nuoc, hoc nuoc, dat nuoc
nien cac » vien cac, dien cac, bien cac
thu nang » thi nang, thu hang, thu bang
vu sach » vu bach, vu khach
su sach » so sach
x hoi » xa hoi, o hoi, x ho

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) OR (vu sach)) thu nang x hoi. thieu nien cac nuoc van hanh vi ((su triet) or (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) thu nang x hoi. thieu nien cac nuoc van hanh vi ((su triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((su sach) OR (vu sach)) thu nang x hoi. thieu nien cac nuoc van hanh vi ((su triet) or (ve triet))".
• Adding a wildcard symbol may retrieve word variants: ((su sach) OR (vu sach)) thu nang x hoi. thieu nien cac nuoc van hanh vi ((su triet) or (ve triet))*.