Original sentence: ) Several newspapers accused Nijkamp of recycling material from his own work and used that of others, both without proper citations.Arnold Heertje denounced Nijkamp for the alleged theft of intellectual property, while the VU's rector, Frank van der Duyn Schouten, maintained that Nijkamp had acted improperly but had not committed plagiarism.In January 2014 some Dutch media conducted investigations of Nijkamp's publications and leveled accusations of self-plagiarism, and asserted that the VU knew of the alleged misconduct
Edited sentence: ) When the media reported that Nijkamp regularly recycled material from his own work and used that of others, both without proper citations, economists such as Arnold Heertje denounced Nijkamp for theft of intellectual property, while the VU's rector, Frank van der Duyn Schouten, maintained that Nijkamp had acted improperly but had not committed plagiarism.However, in January 2014 the media reported that Nijkamp's lengthy publication record was due in large part to self-plagiarism, something his employer, the VU, had been informed of months before