Perhaps you should try some spelling variations:
thanh hoai » thanh hoa, thanh hai, thanh oai
van thanh » ban thanh, van tuan
hieu van » hieu va, thien van, hieu ve
hoai cuu » hoi cua, hoa cua, hoai thu
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
sach tu » sach thu, cach tu, sach uu
nang xa » nang x, lang xa, nang ma
sach ty » sach y, sach thu, xach tay
cuu tre » cua tre, cau tren, cau treo

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