text: * The book REFRESH – life extension of existing and new welded steel structures. can be ordered under the number  at FOSTA – Research Association for Steel Application Association in Germany Düsseldorf.
  * Stahlbau September 2009, 78-year, ISSN 0038-9145 A6449
  * IIW Recommendations for the HFMI Treatment For Improving the Fatigue Strength of Welded Joints. Autoren: Gary B. Marquis, Zuheir Barsoum, https://www.springer.com/de/book/9789811025037
  *DASt-Recommendation - 026 Weld Assessment for fatigue stressed constructions, using high frequency impact hammer treatments, Stahlbau Verlags- und Service GmbH,