apalike+bibtex: letter to duplicate author-year is added not only to the key, but also to the publication year

Question

I've noticed a weird behavior in the generated list of references.

Bibliography included like:

\bibliographystyle{apalike}
\bibliography{path/to/bib}

No weird packages included (but maybe my template does?). I'm definitely not using natbib (grep -r natbib in project folder doesn't return anything). I build the bibliography with bibtex.

.bib:

@inproceedings{Akrour,
author = {Akrour, Riad and Tateo, Davide and Peters, Jan},
booktitle = {1st Workshop on Deep Continuous-Discrete Machine Learning},
organization = {TU Darmstadt},
title = {{Towards Reinforcement Learning of Human Readable Policies}},
year = {2019}
}

@inproceedings{Akrour2019,
address = {Long Beach, California, USA},
author = {Akrour, Riad and Pajarinen, Joni and Neumann, Gerhard and Peters, Jan},
booktitle = {Proceedings of the 36th International Conference on Machine Learning},
pages = {181--190},
publisher = {PMLR},
title = {{Projections for approximate policy iteration algorithms}},
volume = {97},
year = {2019}
}

Generated .bbl:

\bibitem[Akrour et~al., 2019a]{Akrour2019}
Akrour, R., Pajarinen, J., Neumann, G., and Peters, J. (2019a).
\newblock {Projections for approximate policy iteration algorithms}.
\newblock In {\em Proceedings of the 36th International Conference on Machine Learning}, volume~97, pages
  181--190, Long Beach, California, USA. PMLR.

\bibitem[Akrour et~al., 2019b]{Akrour}
Akrour, R., Tateo, D., and Peters, J. (2019b).
\newblock {Towards Reinforcement Learning of Human Readable Policies}.
\newblock In {\em 1st Workshop on Deep Continuous-Discrete Machine Learning}, TU Darmstadt.

Notice the publication year in the parentheses in [Akrour et al., 2019a] Akrour, R., Pajarinen, J., Neumann, G., and Peters, J. (2019a). I think it should only be (2019), shouldn't it? How do I achieve that? Or can it be some weirdness in the template I use?

Answer 1

Although I've learned in the comments that what I'm trying to achieve might not be the best idea, I found a way to do it.

I needed to edit the file apalike.bst distributed with my tex like this:

*** /usr/share/texlive/texmf-dist/bibtex/bst/base/apalike.bst   2020-04-30 05:30:21.838947719 +0200
--- ctu-apalike.bst 2020-04-30 05:31:59.251578754 +0200
***************
*** 121,127 ****
  { year empty$
      { "empty year in " cite$ * warning$ }
      { write$
!       " (" year * extra.label * ")" *
        mid.sentence 'output.state :=
      }
    if$
--- 121,127 ----
  { year empty$
      { "empty year in " cite$ * warning$ }
      { write$
!       " (" year * ")" *
        mid.sentence 'output.state :=
      }
    if$