132926 Small graphics job

Hi, I have an article that was first scanned from print into .jpg files. Then the .jpg files were combined to a .pdf file. 18 pages (each a bit larger then A4) Now this .pdf file is 11 Mb. I zipped it, but then it was still 11 Mb.... Can reduce this .pdf to about 3 Mb (and still keep it legible)? I posted this before, but the person I selected never responded. I tried to attach the file, but it is too big. BR Jaap