Bundle lot of 4 Alfred Hitchcock and the Three Investigators series books, vintage format B editions published by Armada, paperbacks in good condition.  Free postage in Australia.  Selling other 3 Investigators books, check out my other items for sale.  Titles are:

2 The Mystery of the Stuttering Parrot

16 The Mystery of the Coughing Dragon

15 The Mystery of the Flaming Footprints

23 The Mystery of the Invisible Dog