[skip ci] Update README.md

README.md

@@ -2,7 +2,7 @@
 [![Documentation Status](https://readthedocs.org/projects/metall/badge/?version=latest)](https://metall.readthedocs.io/en/latest/?badge=latest)
 [![Deploy API Doc](https://github.com/LLNL/metall/actions/workflows/deploy-api-doc.yml/badge.svg?branch=master)](https://github.com/LLNL/metall/actions/workflows/deploy-api-doc.yml)
 
-Metall: A Persistent Memory Allocator For Data-Centric Analytics
+Metall: A Persistent Memory Allocator for Data-Centric Analytics
 ===============================================
 
 * Provides rich memory allocation interfaces for C++ applications that
@@ -117,10 +117,13 @@ doxygen ../docs/Doxyfile.in
 
 ## Metall: A Persistent Memory Allocator Enabling Graph Processing
 
-[Paper PDF](https://www.osti.gov/servlets/purl/1576900)
+* [Paper PDF](https://www.osti.gov/servlets/purl/1576900)
 
-[IEEE Xplore](https://ieeexplore.ieee.org/document/8945094)
+* [IEEE Xplore](https://ieeexplore.ieee.org/document/8945094)
 
+## Metall: A Persistent Memory Allocator for Data-Centric Analytics (latest publication, preprint)
+
+* [arXiv](https://arxiv.org/abs/2108.07223)
 
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