1
worldometers.info/books
2
mentalfloss.com/article/85305/how-many-books-have-ever-been-published
3
ideas.bkconnection.com/10-awful-truths-about-publishing
5
Bookmate.
6
ourworldindata.org/marriages-and-divorces#marriages-in-many-countries-are-getting-longer
7
youtube.com/channel/UCW1qc3MiEbujmDKT2VyogRg?sub_confirmation=1