sources, including Deputy Foreign Minister Gernot Erler, Greens leader Reinhard Buetikofer and SPD deputy Ulrich Kelber. And during Tony Blair's visit end of May 2007, the British group BP signed a natural gas contract for 900 million dollars. Furthermore, Le Parisien alleged on 13 August 2007 that the agreement concerning nuclear technologies did not concern desalinization of sea water, but focused in particular on the ERP third-generation nuclear reactor, worth $3 billion. The Parisian newspaper cited Philippe Delaune, the deputy of the deputy director of international affairs of the CEA atomic agency. It is the main share-holder of Areva, the firm which products ERP reactors. Although the French President denied any relationship between the deal with Areva and the liberation of the six, Le Parisien points out a troubling chronology: Areva was called to present its products to Libya at the end of June 2007, a short time before the release of the six. The French Socialist Party, through the voice of Jean-Louis Bianco, declared that this deal was "geopolitically irresponsible." The German government also denounced the agreement. Through Siemens, they retain 34% of the shares of Areva's subsidiary in charge of building the ERP (Areva NP). This information from Le Parisien was immediately denied by Areva. Areva's spokesman did admit that negotiations had taken place early June 2007, but that no particular technology transfer had been agreed upon. Furthermore, Philippe Delaune, the CEA's spokesman, added that in any case, any transfer concerning the ERP technology would take at least ten or fifteen years. While Areva did admit that general negotiations had taken place, Nicolas Sarkozy formally dismissed all of the story, claiming it was "false." Bulgarian President Georgy Parvanov also claimed that the arms and nuclear agreements were not related to the release of the nurses. Books Three of the Bulgarian medics published auto-biographical books regarding the trial. Kristiyana Vulcheva's 8 and a half years hostage of Ghaddafi premiered in 2007. Snezhana Dimitrova's In Gaddafi's Cage was published a month later. In 2009 Valya Cherveniashka wrote her version of the story together with Nikolay Yordanov in Notes from Hell. Her book was published in South Africa in 2010, and re-issued worldwide as e-book in Bulgarian, English and French. In 2018 the English language edition was released as audiobook. Diplomatic front There have been a number of diplomatic efforts to resolve the crisis. One of Muammar Gaddafi's sons Saif al-Islam