Brummer & Brummer Oy, Raiso, Finland
Domus, nos. 329, 336, April, November, 1957, n.p. for a similar example
Marianne Aav, Rosa Barovier Mentasti and Gordon Bowyer, et al., Tapio Wirkkala - eye, hand and thought, exh. cat., Museum of Art and Design, Helsinki, 2000, pp. 144, 353 for a similar example