ubuntu 18 release file missing

[vackosar]

Err:14 http://ppa.launchpad.net/michael-sheldon/deepspeech/ubuntu bionic Release                    
  404  Not Found [IP: 91.189.95.83 80]
Err:15 http://ppa.launchpad.net/michael-sheldon/gst-deepspeech/ubuntu bionic Release
  404  Not Found [IP: 91.189.95.83 80]
Reading package lists... Done   
E: The repository 'http://ppa.launchpad.net/michael-sheldon/deepspeech/ubuntu bionic Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://ppa.launchpad.net/michael-sheldon/gst-deepspeech/ubuntu bionic Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.