Missing chef's family hope book will generate new leads
11 March 2013 Last updated at 11:05 GMT
The family of missing chef Claudia Lawrence are hoping a new book will generate new leads, four years after her disappearance.
She was reported missing in March 2009 after failing to turn up for work at the kitchen at the University of York.
Detectives have repeatedly said they believe she was murdered.
Jessica Shiddell reports.