Flugge-Lotz, Irmgard. "Frontmatter". Discontinuous Automatic Control, Princeton: Princeton University Press, 1953, pp. i-iv. https://doi.org/10.1515/9781400877218-fm
Flugge-Lotz, I. (1953). Frontmatter. In Discontinuous Automatic Control (pp. i-iv). Princeton: Princeton University Press. https://doi.org/10.1515/9781400877218-fm