Louis Keizer was co-owner of the cycle wholesale business Rothschild & Keizer at the Nieuwe Markt 8 in Zwolle. In 1928, the moved the shop to the Oudegracht 196 in Utrecht. His business partner was Michel Moritz Rothschild.
Addition of a visitor of the website
In addition, a Jokos file (number 12168) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.