Deaton,
the songs you named are all very aged. So, without following Chris idea, you should search for "middle-age" italian artists, from 1965 to 1990.

I surely forget someone, but you can search for names like:

(males) Claudio Villa, Massimo Ranieri, Gianni Morandi, Tony Renis, Little Tony, Bobby Solo, Adriano Celentano, Pino Donaggio, Sergio Endrigo, Teddy Reno, Nicola di Bari, Fred Bongusto, Bruno Lauzi

(females) Nilla Pizzi, Iva Zanicchi, Anna Identici, Rita Pavone, Gigliola Cinquetti, Mina, Marisa Sannia, Ornella Vanoni, Wilma Goich, Milva, Betty Curtis

Another clue: in Italy we have a big yearly songs festival called SanRemo. In this page:
http://www.hitparadeitalia.it/sanremo/

you will find the list of each song of any year, along with the singer. Note that, around 1965, they presented the songs in both italian and international version, so you will have the same song singed by an italian singers (with italian words) and by an international singer (almost all from USA, England or France) with translated (and adapted) lirycs.

Good luck!