The Mathieu group $M_{12}$ and its pseudogroup extension $M_{13}$.

Conway, John H., Elkies, Noam D., and Martin, Jeremy L.. "The Mathieu group and its pseudogroup extension .." Experimental Mathematics 15.2 (2006): 223-236. <http://eudml.org/doc/231908>.

@article{Conway2006,
author = {Conway, John H., Elkies, Noam D., Martin, Jeremy L.},
journal = {Experimental Mathematics},
keywords = {Mathieu groups; finite projective planes; Golay code; Hadamard matrices},
language = {eng},
number = {2},
pages = {223-236},
publisher = {Taylor & Francis, Philadelphia},
title = {The Mathieu group and its pseudogroup extension .},
url = {http://eudml.org/doc/231908},
volume = {15},
year = {2006},
}

TY - JOUR
AU - Conway, John H.
AU - Elkies, Noam D.
AU - Martin, Jeremy L.
TI - The Mathieu group and its pseudogroup extension .
JO - Experimental Mathematics
PY - 2006
PB - Taylor & Francis, Philadelphia
VL - 15
IS - 2
SP - 223
EP - 236
LA - eng
KW - Mathieu groups; finite projective planes; Golay code; Hadamard matrices
UR - http://eudml.org/doc/231908
ER -