G.B. Halsted (George Bruce Halsted) was a mathematics teacher at the University of Texas at Austin in the early twentieth century. He was interested in and a supporter of non-Euclidean geometry and translated into English the books of its two founders, Janos Bolyai and Nikolai I. Lobachevsky. He advocated the teaching of non-Euclidean geometry in high school instead of traditional Euclidean geometry, which he viewed as obsolete.
- A History of Mathematics Education in the United States and Canada National Council of Teachers of Mathematics (NCTM) yearbook.