Perhaps you should try some spelling variations:
thien van » thi van
so triet » su triet, so thiet, bo triet
dinh tai » dinh toai, dinh tri, dinh thi
van chat » cao chat
tu sach » thu sach, su sach, te sach
v nang » va nang, vu nang, van nang
y nang » ky nang, ly nang, may nang
soc va » hoc va, doc va, goc va
loc va » hoc va, luc va
tai so » tai sao, dai so, tai co

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ((y nang) or (v nang)) cau hoi. thien van chat ((soc va) or (loc va)) dinh tai so triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ((y nang) OR (v nang)) cau hoi. thien van chat ((soc va) OR (loc va)) dinh tai so triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ((y nang) or (v nang)) cau hoi. thien van chat ((soc va) or (loc va)) dinh tai so triet*.