Fix typo in citation [skip ci]

README.md

@@ -29,7 +29,7 @@ Data files are licensed under [CC-BY 4.0](https://creativecommons.org/licenses/b
 If you use paleokalmag, please cite the corresponding paper
 
 > Schanner, M. A.; Korte, M.; Holschneider, M. (2021)  
-> ArchKalMag14k: A Kalman-filter based global geomagnetic model for the Holocene  
+> ArchKalmag14k: A Kalman-filter based global geomagnetic model for the Holocene  
 > Earth and Space Science Open Archive. https://doi.org/10.1002/essoar.10507955.1  
 [![DOI](https://img.shields.io/badge/DOI-10.1002%2Fessoar.10507955.1-blue.svg)](https://doi.org/10.1002/essoar.10507955.1)