1. Abbott BP, et al., Phys Rev Letters. 2016;116:061102.
2. Born M, Wolf E. Principles of Optics, (Mc Millan, New York 1964). Lugiato L, Strini G, De Martini F, "Squeezed states in SH generation". Optics Letters. 1983;8:256.
3. Misner CW, Thorne KS, Wheeler JA. Gravitation (Freeman, San Francisco), 1973.
4. The present short historical recollection is based on the content of the book: Giazotto A, Parlangeli A. "La Musica nascosta dell'Universo" (Einaudi 2018). This small book, published after the death of Adalberto Giazotto was a tribute to the his strenuous, highly inspiring endeavour by his friends and collaborators in Italy, France and US. Luckily enough Adalberto, gravely ill, was able to see the success of his long sought idea, first realized by LIGO in 2016, and one year later also by VIRGO in Pisa just three months before his death occurred in November 18, 2017 at the age 77: this was the end of the life of a great scientist. Adalberto was still living his last days when the Nobel prize 2017 was awarded to: Rai Weiss, Kip Thorne and Barry Barish.
5. The fundamental nonlocality of physics was first identified by Isaac Newton in the XV century. "...Gravity must caused by an Agent acting constantly to certain Laws, but whether this Agent is material or immaterial, I have left to the Consideration of my Readers…" (I. Newton's Papers and Letters on Natural Philosophy, pag.302. Harvard U.Press Cambridge, Mass 1958). A more extensive sentence by Newton is reported by: N. Gisin, "Can Relativity be considered complete?" 2005; arXiv: quant-ph/0512168v1.