Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
toc sach » hoc sach, doc sach, nuoc sach
va triet » va thiet, va trien, ve triet
hieu ve » hieu va, hieu van
truc va » thuc va, thuc vat, trung va
dinh su » dinh so, hinh su, dinh cu
y nang » ky nang, ly nang, v nang
ve cam » ve cham, ve cac, va cam
luc va » duc va, tuc va, loc va
x hoi » xa hoi, o hoi, x ho
su va » su van, tu va

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) OR (thuoc sach)) y nang x hoi. hieu ve cam ((luc va) or (truc va)) dinh su va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (thuoc sach)) y nang x hoi. hieu ve cam ((luc va) OR (truc va)) dinh su va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) OR (thuoc sach)) y nang x hoi. hieu ve cam ((luc va) or (truc va)) dinh su va triet".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) OR (thuoc sach)) y nang x hoi. hieu ve cam ((luc va) or (truc va)) dinh su va triet*.