• Research and development of Tallinn University of Technology at the service of Estonian society : [preface]Keevallik, AndresTUT research and development 20112012 / p. 3 https://www.ester.ee/record=b2689163*est
• Research and development of Tallinn University of Technology at the service of Estonian society : [preface]Keevallik, AndresTUT research and development 20102011 / p. 3 https://www.ester.ee/record=b2689163*est