Birkhoff, George D. On drawings composed of uniform straight lines. (English) Zbl 0024.28501 J. Math. Pures Appl., IX. Sér. 19, 221-236 (1940). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Keywords:Convex geometry, integral geometry PDFBibTeX XMLCite \textit{G. D. Birkhoff}, J. Math. Pures Appl. (9) 19, 221--236 (1940; Zbl 0024.28501)