is the focus of a book published by Margaret Power in 1991. It has been suggested that higher levels of aggression and conflict with other chimpanzee groups in the area were due to the feeding, which could have created the "wars" between chimpanzee social groups described by Goodall, aspects of which she did not witness in the years before artificial feeding began at Gombe. Thus, some regard Goodall's observations as distortions of normal chimpanzee behaviour. Goodall herself acknowledged that feeding contributed to aggression within and between groups, but maintained that the effect was limited to alteration of the intensity and not the nature of chimpanzee conflict, and further suggested that feeding was necessary for the study to be effective at all. Craig Stanford of the Jane Goodall Research Institute at the University of Southern California states that researchers conducting studies with no artificial provisioning have a difficult time viewing any social behaviour of chimpanzees, especially those related to inter-group conflict. Some recent studies, such as those by Crickette Sanz in the Goualougo Triangle (Congo) and Christophe Boesch in the Taï National Park (Ivory Coast), have not shown the aggression observed in the Gombe studies. However, other primatologists disagree that the studies are flawed; for example, Jim Moore provides a critique of Margaret Powers' assertions and some studies of other chimpanzee groups have shown aggression similar to that in Gombe even in the absence of feeding. Plagiarism and Seeds of Hope On 22 March 2013, Hachette Book Group announced that Goodall's and co-author Gail Hudson's new book, Seeds of Hope, would not be released on 2 April as planned due to the discovery of plagiarised portions. A reviewer for The Washington Post found unattributed sections that were copied from websites about organic tea, tobacco, and an "amateurish astrology site", as well as from Wikipedia. Goodall apologised and stated, "It is important to me that the proper sources are credited, and I will be working diligently with my team to address all areas of concern. My goal is to ensure that when this book is released it is not only up to the highest of standards, but also that the focus be on the crucial messages it conveys." The book was released on 1 April 2014, after review and the addition of 57 pages of endnotes. In popular culture Gary Larson cartoon incident One of Gary Larson's Far Side cartoons shows two