Format for multiple affiliations

paper.md

@@ -13,7 +13,7 @@ authors:
     affiliation: 1
   - name: Simon J Goring
     orcid: 0000-0002-2700-4605
-    affiliation: [2, 3]
+    affiliation: "2, 3"
 affiliations:
   - name: HT Data
     index: 1
@@ -39,4 +39,4 @@ The `neotoma` R package [@goring2015neotoma] leveraged the Neotoma Paleoeocology
 
 We acknowledge contributions from the Neotoma Paleoecology Community, the participants of our workshops for the European Pollen Database, American Quaternary Association and the International Association of Limnologists/International Paleolimnology Association, and members of the EarthCube community. This work was funded through a grant to SJG from the National Science Foundation (NSF-1948926).
 
-# References
+# References