Perhaps you should try some spelling variations:
thanh hoai » thanh hoa, thanh hai, thanh oai
van thanh » ban thanh, van tuan
hoai cuu » hoi cua, hoa cua, hoai thu
hieu van » thien van, lieu va, hieu ve
so sach » so sanh, bo sach, co sach
hieu va » lieu va, hieu qua
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
cuu tre » cua tre, cau tren, cau treo
tu nano » truc nano
tu nang » tru nang, tu nong, tu lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((tu nang) OR (tu nano)) xa hoi. ((hieu van) or (hieu va)) cam duc van thanh hoai cuu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((tu nang) OR (tu nano)) xa hoi. ((hieu van) OR (hieu va)) cam duc van thanh hoai cuu tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((tu nang) OR (tu nano)) xa hoi. ((hieu van) or (hieu va)) cam duc van thanh hoai cuu tre".
• Adding a wildcard symbol may retrieve word variants: so sach ((tu nang) OR (tu nano)) xa hoi. ((hieu van) or (hieu va)) cam duc van thanh hoai cuu tre*.