Unit blocks have probably been used in some Icelandic preschools since 1950 or 1960, but a turning point occurred when one of the author's teachers from the Iceland University of Education (Fosturskoli Islands), Jonina Tryggvadottir, returned from studying with Harriet Cuffaro at Bank Street College in New York City.
Einarsdóttir, K. (2014). When Unit Blocks Came to Gardaborg. Occasional Paper Series, 2014 (32). Retrieved from https://educate.bankstreet.edu/occasional-paper-series/vol2014/iss32/4