Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
vat dinh » va dinh, van dinh, vat sinh
dinh tai » dinh toai, dinh tri, dinh thi
ky dang » ky nang, ky danh
tai cua » thai cua, tai cuc, tri cua
ky anh » ky danh, ly anh, ty anh
van am » van nam, van lam, van dam
cua te » cua tu
thuc » thu

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 (hoc sach)) ((ky dang) or (ky anh)) xa hoi. hieu van am thuc vat dinh tai cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (hoc sach)) ((ky dang) OR (ky anh)) xa hoi. hieu van am thuc vat dinh tai cua te.
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (hoc sach)) ((ky dang) or (ky anh)) xa hoi. hieu van am thuc vat dinh tai cua te*.