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Although the notion of higher dimensions goes back to René Descartes , substantial development of a higher-dimensional geometry only began in the 19th century , via the work of Arthur Cayley , William Rowan Hamilton , Ludwig Schläfli and Bernhard Riemann .
 person: René Descartes; person: Arthur Cayley; person: William Rowan Hamilton; person: Ludwig Schläfli; person: Bernhard Riemann
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: René Descartes; person: Arthur Cayley; person: William Rowan Hamilton; person: Ludwig Schläfli; person: Bernhard Riemann