"Statement of Information"(PDF). businesssearch.sos.ca.gov. California Secretary of State. 28 August 2018. Retrieved 13 February 2019.
"Statement of Information"(PDF). businesssearch.sos.ca.gov. California Secretary of State. 3 October 2018. Archived from the original on 14 February 2019. Retrieved 13 February 2019.
"Signal Technology Foundation". OpenCorporates. Delaware Department of State: Division of Corporations. 15 July 2018. Retrieved 13 February 2019.
"Signal Messenger, LLC". OpenCorporates. Delaware Department of State: Division of Corporations. 15 July 2018. Archived from the original on 14 February 2019. Retrieved 13 February 2019.
"Signal Messenger, LLC". OpenCorporates. Delaware Department of State: Division of Corporations. 15 July 2018. Archived from the original on 14 February 2019. Retrieved 13 February 2019.
"Statement of Information"(PDF). businesssearch.sos.ca.gov. California Secretary of State. 3 October 2018. Archived from the original on 14 February 2019. Retrieved 13 February 2019.