Encyclopedia Brown and the case of the disgusting sneakers
Donald J. Sobol
America's Sherlock Holmes in sneakers continues his war on crime in ten more cases, the solutions to which are found in the back of the book.

by Joseph Rosenbloom (1983)
A collection of fourteen "case histories" which Maximilian, the amazing twelve-year-old Manhattan detective, was instrumental in solving.
Donald J. Sobol
America's Sherlock Holmes in sneakers continues his war on crime in ten more cases, the solutions to which are found in the back of the book.
Robert Arthur
A competitor of the Hardy Boys/Nancy Drew books, this Hitchcock-supported series mostly written by Robert Arthur concerns Jupiter Jones and his middle-school-age amateur detective club which operates out of one of the parents' businesses. It's a junkyard, and as such offers lots of cover for the clubhouse location, storage and getaways from nefarious characters. "Fiery Eye" follows the search for a jewel inheritance through a riddle in a poem, clues hidden in Greek and Roman busts and a burial location requiring them to note the angle of the sun at a specific hour without being seen by pursuing crooks. Originally printed in the 1960's and reprinted several times; available today at many used bookstores.
Carolyn Keene
Nancy Drew and friends Bess and George track a group of swindlers and kidnappers from New York to Mexico City to Los Angeles where they finally solve the mystery of the Triple Hoax.
Mary Higgins Clark
After college, best friends Erin Kelley and Darcy Scott move to the city to pursue exciting careers; Erin is a promising jewelry designer, Darcy finds success as a decorator. On a lark, Darcy persuades Erin to help their TV producer friend research the kinds of people who place personal ads. It seems like innocent fun...until Erin disappears. Erin's body is found on an abandoned Manhattan pier -- on one foot is her own shoe, on the other, a high-heeled dancing slipper. Soon after, startling communiques from the killer reveal that Erin is not the first victim of this "dancing shoe murderer." And, if the killer has his way, she won't be his last. Next on his death list is Darcy.