Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
yen lang » den lang, ten lang, yen giang
thanh vi » hanh vi, thanh va, thanh ve
cam thuc » nam thuc, cam thu, can thuc
te sach » toc sach
hieu ve » hieu va, hieu van
o lang » hoa lang, hoi lang
vi cua » vai cua, di cua
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ((yen lang) or (o lang)) xa hoi. hieu ve ((cam thuc) OR (am thuc)) van thanh vi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ((yen lang) OR (o lang)) xa hoi. hieu ve ((cam thuc) OR (am thuc)) van thanh vi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ((yen lang) or (o lang)) xa hoi. hieu ve ((cam thuc) OR (am thuc)) van thanh vi cua te".
• Adding a wildcard symbol may retrieve word variants: te sach ((yen lang) or (o lang)) xa hoi. hieu ve ((cam thuc) OR (am thuc)) van thanh vi cua te*.