Natbib incorrectly formatting multiple citation to repeated author

Question

I am attempting to use natbib for my references in a latex document (article class) but it is exhibiting some very strange behaviour. When citing multiple papers as;

\documentclass{article}
\usepackage{natbib}
\bibliographystyle{abbrvnat}
\begin{document}
....
\citep{LIGO2,LIGO3,LIGO4,LIGO5}
....
\bibliography{references}
\end{document}

I get output that looks like;

[Abbott et al., 2016b,0,0,0] .

I think this is some built in feature of natbib that is not showing the 4 separate references because they all have the same author (this doesn't happen when I change the authors in references.bib). How do I turn this off so that it displays;

[Abbott et al., 2016b, Abbott et al., 2017a, Abbott et al., 2017b, Abbott et al., 2017c] ?

---

Bibliography entries are;

@article{LIGO2,
  title = "{GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence}",
    author = "Abbott, B. P. and others",
  collaboration = {LIGO Scientific Collaboration and Virgo Collaboration},
  journal = {Phys. Rev. Lett.},
  volume = {116},
  issue = {24},
  pages = {241103},
  numpages = {14},
  year = {2016},
  month = {Jun},
  publisher = {American Physical Society},
  doi = {10.1103/PhysRevLett.116.241103},
}


@article{LIGO3,
  title = "{GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2}",
  author = "Abbott, B. P. and others",
  collaboration = {LIGO Scientific and Virgo Collaboration},
  journal = {Phys. Rev. Lett.},
  volume = {118},
  issue = {22},
  pages = {221101},
  numpages = {17},
  year = {2017},
  month = {Jun},
  publisher = {American Physical Society},
  doi = {10.1103/PhysRevLett.118.221101},
}

@article{LIGO4,
      author         = "Abbott, B.P. and others",
      title          = "{GW170817: Observation of Gravitational Waves from a
                        Binary Neutron Star Inspiral}",
      collaboration  = "Virgo, LIGO Scientific",
      journal        = "Phys. Rev. Lett.",
      volume         = "119",
      year           = "2017",
      number         = "16",
      pages          = "161101",
      doi            = "10.1103/PhysRevLett.119.161101",
      eprint         = "1710.05832",
      archivePrefix  = "arXiv",
      primaryClass   = "gr-qc",
      reportNumber   = "LIGO-P170817",
      SLACcitation   = "%%CITATION = ARXIV:1710.05832;%%"
}

@article{LIGO5,
      author         = "Abbott, B. P. and others",
      title          = "{GW170814: A Three-Detector Observation of Gravitational
                        Waves from a Binary Black Hole Coalescence}",
      collaboration  = "Virgo, LIGO Scientific",
      journal        = "Phys. Rev. Lett.",
      volume         = "119",
      year           = "2017",
      number         = "14",
      pages          = "141101",
      doi            = "10.1103/PhysRevLett.119.141101",
      eprint         = "1709.09660",
      archivePrefix  = "arXiv",
      primaryClass   = "gr-qc",
      SLACcitation   = "%%CITATION = ARXIV:1709.09660;%%"
}

Answer 1

(posting my earlier comment as an answer, so that this posting can be checked off has having received an "official" answer)

There's a slight error in the author field of entry LIG04. The field should be changed from

Abbott, B.P. and others

to

Abbott, B. P. and others

(Note the space between "B." and "P.".) That way, all four entries in question will have the exact same author field. Once this fix is made, running LaTeX-BibTeX-LaTeX-LaTeX on your code produces the following output:

[Abbott et al., 2016, 2017a,b,c]

I believe that this is what you want -- or, at least, what you should want.