diff --git a/refs.bib b/refs.bib
index 32f9561..7400589 100644
--- a/refs.bib
+++ b/refs.bib
@@ -51,7 +51,7 @@
 
 @techreport{tantau2015tikz,
   title={The TikZ and PGF Packages (Manual for version 3.1.8b)},
-  author={Tantau, Tilll},
+  author={Tantau, Till},
   year={2020},
   institution={Institut f{\"u}r Theoretische Informatik Universit{\"a}t zu L{\"u}beck},
   url={http://mirrors.ctan.org/graphics/pgf/base/doc/pgfmanual.pdf}