The group of pre-teen detectives is led by 10-year-old Jack P. McGurk. Members of the McGurk Detective Agency included Joey Rockaway, Willie "The Nose" Sandowsky, Wanda Greig, Gerald "Brains" Bellingham, and later, Mari Yoshimura. The series started with The Nose Knows in 1974 (ISBN0448057212) and continued through 24 volumes to the final adventure The Case of the Wiggling Wig in 1996 (ISBN0689800827).
Books
The Nose Knows (1974)
Dolls in Danger (1974 ; aka "Deadline for McGurk")
The Case of the Condemned Cat (1975)
The Menaced Midget (1975)
The Case of the Nervous Newsboy (1976)
The Great Rabbit Robbery (1976; aka "The Great Rabbit Rip-Off")