Perhaps you should try some spelling variations:
nguoi sach » nguoi san
nuoc sach » hoc sach, cuoc cach, cuon sach
thanh tai » thanh hai, thanh toan, doanh tai
va thanh » gia thanh, ban thanh, va tinh
hieu cua » hieu qua, dieu cua, bieu cua
ca viet » va viet, co viet, hoa viet
ty hang » ly hang, ty xang, thi hang
hang xa » hoang xa, hang va, hang ca
cac co » cac cong
tai ca » tai cac, tai cao, tai cua
cac bo » bac bo

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((nuoc sach) OR (nguoi sach)) ty hang xa hoi. hieu cua ((cac bo) or (cac co)) va thanh tai ca viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((nuoc sach) OR (nguoi sach)) ty hang xa hoi. hieu cua ((cac bo) OR (cac co)) va thanh tai ca viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((nuoc sach) OR (nguoi sach)) ty hang xa hoi. hieu cua ((cac bo) or (cac co)) va thanh tai ca viet".
• Adding a wildcard symbol may retrieve word variants: ((nuoc sach) OR (nguoi sach)) ty hang xa hoi. hieu cua ((cac bo) or (cac co)) va thanh tai ca viet*.