A researcher at the University of Sunderland has shed light on the disappearance of a highly profitable section of the publishing industry - girls' comics.
Mel Gibson, awarded a PhD for her research, said: "In the 1960s and 1970s, girls' comics such as Bunty and Jackie were selling 1 million copies a week - now there are none around. I wanted to find out why a culture that big vanished.
"I found two reasons for this. In the 1980s there was a major shift in comic culture. The arrival of girls' magazines such as Bliss and Sugar reflected the growth of girls consumer culture.
"These new magazines were filled with tips on make-up and pictures of pop and television stars, with little in the way of stories. It was also much cheaper to produce them."
Ms Gibson's research shows that 5 per cent of comic readers are female. She is looking for publishers for her thesis.