array(3) {
  [0]=>
  int(15501)
  [1]=>
  string(175) "Schumann A.W., Zaman Q.U. Software development for real-time ultrasonic mapping of tree canopy size. Computers and electronics in agriculture. 2005. vol. 47. no. 1. pp. 25-40."
  [2]=>
  int(1)
}
<h1>DB Error 230: Duplicate entry '15501-1' for key 'citations.citations_submission_seq'</h1>