Update references.bib

Author: mhjensen

doc/src/FuturePlans/references.bib

@@ -157,4 +157,13 @@ @misc{tene2026solvinglinearequationsquantum
       archivePrefix={arXiv},
       primaryClass={quant-ph},
       url={https://arxiv.org/abs/2604.26098}, 
+}
+@misc{payn2026observablemeasuresmultipartiteentanglement,
+      title={Observable measures of multipartite entanglement}, 
+      author={Francois Payn and Davide Girolami},
+      year={2026},
+      eprint={2605.01375},
+      archivePrefix={arXiv},
+      primaryClass={quant-ph},
+      url={https://arxiv.org/abs/2605.01375}, 
 }