Professor Velner and protection of the Gulf of FinlandKajosaari, EeroHarald-Adam Velner - engineer and scientist1994 / p. 37-41 https://www.ester.ee/record=b1053757*est Professor Velner ja Soome lahe kaitseKajosaari, EeroHarald-Adam Velner - insener ja veeteadlane1993 / lk. 35-38 https://www.ester.ee/record=b1053756*est