Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dinh tai » dinh toai, dinh tri, dinh thi
hieu van » thien van, lieu va, hieu ve
ve triet » va trien, su triet
ky lang » ky nang, ky dang, ky tang
lang ha » long ha
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
cau xuc » cam xuc, cau luc, cau truc
va dinh » van dinh, va kinh, va tinh
xuc va » duc va, tuc va, luc va
ha hoi » hoa hoi, ha noi, xa hoi
cua tu » cua tuc, cua su, cua cu

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 lang ha hoi. ((hieu van) or (hieu va)) cau xuc va dinh tai ((ve triet) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ky lang ha hoi. ((hieu van) OR (hieu va)) cau xuc va dinh tai ((ve triet) OR (cua tu)).
• Adding a wildcard symbol may retrieve word variants: toc sach ky lang ha hoi. ((hieu van) or (hieu va)) cau xuc va dinh tai ((ve triet) or (cua tu))*.