arxiv:1907.02550
%%% BibTeX

@Article{Fuentes-Martin:2019bue,
 author        = "Javier Fuentes-Martin and Mario Reig and Avelino Vicente",
 title         = "4321... axion!",
 year          = "2019",
 eprint        = "1907.02550",
 archivePrefix = "arXiv",
 primaryclass = "hep-ph",
}

@Article{1907.02550, crossref = "Fuentes-Martin:2019bue"}

%%% LaTeX

\cite{Fuentes-Martin:2019bue}

%%% bibitem

\bibitem{Fuentes-Martin:2019bue}
Javier Fuentes-Martin, Mario Reig, Avelino Vicente,
%"4321... axion!",
arXiv:1907.02550.