We are still trying to figure out the best way how to combine several preprints databases that exists at various institutions. Temporarily, we decided to adopt a non-automated insertion of preprints. If you want to insert a preprint to Nečas center database, please send it to preprint-ncmm@karlin.mff.cuni.cz (Jana Pešková).
The legacy preprint database of the "old" Nečas center can be found here or here.