Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
va thanh » gia thanh, ban thanh, va tinh
cua dieu » va dieu
chat tuu » chat huu, chat cua, chat xuc
tu sach » thu sach, su sach, te sach
va chat » van chat, va phat, cao chat
hieu va » lieu va, hieu qua
co viet » so viet, o viet, hoc viet
tuu va » tu va, cuu va, tru va

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

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