Update README.md

Add ref to tsdate paper

README.md

@@ -7,11 +7,16 @@ Infer a tree sequence from genetic variation data
 
 The [documentation](https://tskit.dev/tsinfer/docs/stable) contains details of how to use this software, including [installation instructions](https://tskit.dev/tsinfer/docs/stable/installation.html).
 
-The algorithm, its rationale, and results from testing on simulated and real data are described in the following [Nature Genetics paper](https://doi.org/10.1038/s41588-019-0483-y):
+The initial algorithm, its rationale, and results from testing on simulated and real data are described in the following [Nature Genetics paper](https://doi.org/10.1038/s41588-019-0483-y):
 
 > Jerome Kelleher, Yan Wong, Anthony W Wohns, Chaimaa Fadil, Patrick K Albers and Gil McVean (2019) *Inferring whole-genome histories in large population datasets*. Nature Genetics **51**: 1330-1338
 
-Please cite this if you use ``tsinfer`` in your work. Code to reproduce the results in the paper is present in a [separate GitHub repository](https://github.com/mcveanlab/treeseq-inference).
+_Tsinfer_ versions [0.2.0](https://github.com/tskit-dev/tsinfer/releases/tag/0.2.0) onwards allow missing data and provide a fully parameterised Li & Stephens matching algorithm (i.e. which allows mismatch). These improvements are described in the
+following [Science paper](https://doi.org/10.1126/science.abi8264):
+
+> Anthony Wilder Wohns, Yan Wong, Ben Jeffery, Ali Akbari, Swapan Mallick, Ron Pinhasi, Nick Patterson, David Reich, Jerome Kelleher, and Gil McVean (2022) A unified genealogy of modern and ancient genomes. Science 375: eabi8264
+
+Please cite either or both of these if you use ``tsinfer`` in your work. Code to reproduce the results in the first paper is present in a [separate GitHub repository](https://github.com/mcveanlab/treeseq-inference).
 
 Note that `tsinfer` does not attempt to infer node times (i.e. branch lengths of the
 inferred trees). If you require a tree sequence where the dates of common ancestors