Add Apertif bibentry

texmf/bibtex/bib/apertif.bib

+@INPROCEEDINGS{2018wtfa.confE..16O,
+       author = {{Oosterloo}, T. and {van Leeuwen}, J. and {Van Cappellen}, W. and {Kruithof}, G. and {Jackson}, C.},
+        title = "{Apertif; the next stage}",
+    booktitle = {Westerbork Telescope 50th Anniversary},
+         year = 2018,
+       volume = {361},
+        month = sep,
+          eid = {16},
+        pages = {16},
+       adsurl = {https://ui.adsabs.harvard.edu/abs/2018wtfa.confE..16O},
+      adsnote = {Provided by the SAO/NASA Astrophysics Data System}
+}

texmf/tex/latex/astron/astron.cls

@@ -136,6 +136,7 @@
 }
 
 % Standard bibliography files included in this package
+\addbibresource{apertif.bib}
 \addbibresource{astron.bib}
 \addbibresource{escape.bib}
 \addbibresource{general.bib}