Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
su triet » su viet, su tien, ve triet
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
qua cac » cua cac
xuc va » tuc va, luc va, xac va
dan vi » doan vi, dan va, gan vi
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: toc sach ly nang x hoi. hieu qua cac ((xuc va) or (duc va)) ((dan vi) or (don vi)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach ly nang x hoi. hieu qua cac ((xuc va) OR (duc va)) ((dan vi) OR (don vi)) su triet.
• Adding a wildcard symbol may retrieve word variants: toc sach ly nang x hoi. hieu qua cac ((xuc va) or (duc va)) ((dan vi) or (don vi)) su triet*.