This is an article by an American gynecologist. He seems to have a vested interest in the subject. Seems as though the Italians are also quite knowledgeable in that area. Surprisingly, according to most sexologists, the jury seems to be out on the G-spot.
The study in question, called G-Spot Anatomy: A New Discovery, appears in The Journal of Sexual Medicine and was conducted by Adam Ostrzenski, director of the Institute of Gynecology in St Petersburg. It claims to shed some real light on the existence of the G-spot, through dissection of a cadaver's vaginal wall. From New Scientist :
"He found a clearly defined sac in a layer between the vagina and the urethra close to the perineal membrane. The sac was around 16 millimetres from the upper part of the urethral opening. At less than a centimetre long, it was positioned at a 35-degree angle to the urethra... Inside the sac Ostrzenski found a "worm-like" structure with three distinct regions that broadly "resemble erectile tissue – normally found in areas such as the clitoral body"."