TY - JOUR AU - Mauricio A. Escobar Ruiz AU - Ernest G. Kalnins AU - Willard Miller Jr. AU - Eyal Subag TI - BĂ´cher and Abstract Contractions of $2$nd Order Quadratic Algebras JO - Symmetry, integrability and geometry: methods and applications PY - 2017 VL - 13 UR - http://geodesic.mathdoc.fr/item/SIGMA_2017_13_a12/ LA - en ID - SIGMA_2017_13_a12 ER -