[1] ‘Message read. But what kind of weirdo keeps read receipts on?’, https://www.theguardian.com/technology/2015/aug/17/message-read-but-what-kind-of-weirdo-keeps-read-receipts-on
[2] ‘BlackBerry Messenger dies today, but it’ll never truly be gone’, https://www.theverge.com/2019/5/31/18646429/blackberry-messenger-ending-group-chats-read-receipts-rim-apple-android-imessage
[3] ‘How ‘seen’ messages on Facebook mess with your mental health’, https://www.dazeddigital.com/science-tech/article/38010/1/how-seen-messages-on-facebook-mess-with-your-mental-health
[4] ‘Devastated Snapchatters talk about the heartbreak of losing a Snapstreak after hundreds of days’, https://mashable.com/article/breaking-snapstreak-snapchat-streak
[5] Lynden, James, and Teis Rasmussen. "Exploring the impact of'read receipts' in Mobile Instant Messaging." Tidsskrift for Medier, Erkendelse Og Formidling 5.1 (2017).
[6] ‘Read Receipts: The Psychology of Emotional Manipulation’, https://oozestudios.com.au/read-receipts-the-psychology-of-emotional-manipulation/
[7] ‘Handling notifications in instant messaging systems’, US8572182B2, https://patents.google.com/patent/US9219703B2/