Graphic representation of the periodic table of chemical elements designed as a series table consisting of two parts that are arranged like mirror-images of one another. This table was originated by German chemist Egon Wiberg (1901-1976) in 1936 and classified by chemist Edward G. Mazurs as Type IIC2-6 in his seminal work Types of Graphic Representation of the Periodic System of Chemical Elements (1957). This table appears as Figure 58 on page 128 of Mazurs' 1957 publication.
Mazurs, Edward G., and Egon Wiberg. “Series Table Consisting of Two Mirror-Images (Egon Wiberg, 1936).” Glass, circa 1936–1957. Edward G. Mazurs Collection of Periodic Systems Images, Box 1. Science History Institute. Philadelphia. https://digital.sciencehistory.org/works/xk81jm01t.