What are the characters to the hardy boys?

The main characters are Frank Hardy, the elder brother, Joe Hardy, the younger brother, Fenton Hardy,the father of the hardy boys, their mother (name not known), their aunt, Aunt Trudy (or Gretude in the older series). Sometimes Chet Morton, Phil Cohen and Jillie, their friends; and Iola Morton, Joe's girlfriend and Callie Shaw, Frank's girlfriend are also included in the stories.