**All these papers are now freely available at: https://jnc.psychopen.eu/index.php/jnc/issue/view/293
please use the published version rather than this archive**
These are Author Accepted manuscripts of the Special Issue "Direct and Conceptual Replication in Numerical Cognition" edited by M. Soltanlou and K. Cipora, published in Joural of Numerical Cognition in 2021.