Schwarz, Wolfgang K. Über B-Zwillinge. II. (German) Zbl 0247.10025 Arch. Math. 23, 408-409 (1972). MSC: 11N05 PDFBibTeX XMLCite \textit{W. K. Schwarz}, Arch. Math. 23, 408--409 (1972; Zbl 0247.10025) Full Text: DOI
Indlekofer, Karl-Heinz; Schwarz, Wolfgang K. Über B-Zwillinge. (German) Zbl 0236.10029 Arch. Math. 23, 251-256 (1972). MSC: 11P05 11N05 PDFBibTeX XMLCite \textit{K.-H. Indlekofer} and \textit{W. K. Schwarz}, Arch. Math. 23, 251--256 (1972; Zbl 0236.10029) Full Text: DOI