Compiling error when adding BibTeX entries

Question

I recently made a .bib file with 5 entries and it worked perfectly. However, when I added 5 more entries today, it gave the following error:

Paragraph ended before \OT1\. was complete

When I remove the latest entries I still get the error, but when I replace the .aux, .bib and .tex files with back-upped versions containing 5 entries it works again.

Is there anyone who has any idea as how to solve this error?

The .tex file

\documentclass{scrartcl}
\usepackage[english]{babel}
\usepackage[super]{natbib}
\title{[Insert Title Here]}
\begin{document}
\maketitle
\newpage
\bibliographystyle{unsrt}
\bibliography{refs}
\end{document}

The .bib file

@article{Clark2004,
author    = "Clark, Timothy",
title     = "{QSAR} and {QSPR} based solely on surface properties?",
journal   = "Journal of Molecular Graphics and Modelling",
volume   = "22",
pages    = "519-525",
year      = "2004",
month    = "March",
}

@article{Fabian2009,
author    = "F{\'a}bi{\'a}n, L{\'a}szl{\'o}",
title     = "Cambridge Structural Database Analysis of Molecular Complementary in Cocrystals",
journal   = "Crystal Growth \& Design",
volume   = "9",
number   = "3",
pages    = "1436-1443",
year      = "2009",
month    = "January",
}

@article{Flack2003,
author    = "Flack, H.D. and Bernardinelli, G.",
title     = "The {M}irror of {G}aladriel: looking at chiral and achiral crystal structures",
journal   = "Crystal Engineering",
volume   = "6",
pages    = "213-223",
year      = "2003",
month    = "October",
}

@article{Iggland2014,
author    = "Iggland, Martin and M{\"u}ller, Roland and Mazzotti, Marco",
title     = "On the Effect of Initial Conditions in Viedma Ripening",
journal   = "Crystal Growth \& Design",
volume   = "14",
pages    = "2488-2493",
year      = "2014",
month    = "April",
}

@article{Kirsty2010,
author    = "Anderson, Kirsty M. and Probert, Michael R. and Goeta, Andr{\'e}s E. and Steed, Jonathan W.",
title     = "Size does matter - {T}he contribution of molecular volume, shape and flexibility to the formation of co-crystals and structures with ${Z}'>1$",
journal   = "The Royal Society of Chemistry",
volume   = "13",
pages    = "83-87",
year      = "2010",
month    = "May",
}

@article{Musumeci2011,
author    = "Musumeci, Daniele and Hunter, Cristopher A. and Prohens, Rafel and Scuderi, Serena and McCabe, James F.",
title     = "Virtual cocrystal screening",
journal   = "The Royal Society of Chemistry",
volume   = "2",
pages    = "883-890",
year      = "2011",
month    = "January",
}

@article{Spix2012,
author    = "Spix, Laura and Meekes, Hugo and van Enckevort, Willem J.P. and Vlieg, Elias",
title     = "Complete Deracemization of Proteinogenic Glutamic Acid Using Viedma Ripening on a Metastable Conglomerate",
journal   = "Crystal Growth \& Design",
volume   = "12",
pages    = "5796-5799",
year      = "2012",
month    = "October",
}

@article{Spix2014,
author    = "Spix, Laura and Alfing, Alinda and Meekes, Hugo and van Enckevort, Willem J.P. and Vlieg, Elias",
title     = "Formation of a Salt Enables Complete Deracemization of a Racemic   Compound through Viedma Ripening",
journal   = "Crystal Growth \& Design",
volume   = "14",
pages    = "1744-1748",
year      = "2014",
month    = "February",
}

@article{Steendam2013,
author    = "Steendam, Ren{\'e} R.E. and Harmsen, Bram and Meekes, Hugo and van Enckevort, Willem J.P. and Kaptein, Bernard and Kellogg, Richard M. and Raap, Jan and Rutjes, Floris P.J.T. and Vlieg, Elias",
title     = "Controlling the Effect of Chiral Impurities on Viedma Ripening",
journal   = "Crystal Growth \& Design",
volume   = "13",
pages    = "4776-4780",
year      = "2013",
month    = "September",
}

@article{Viedma2005,
author    = "Viedma, Cristobal",
title     = "Chiral Symmetry Breaking During Crystallization: Complete Chiral Purity Induced by Nonlinear Autocatalysis and Recycling",
journal   = "Physical Review Letters",
volume   = "94",
pages    = "065504",
year      = "2005",
month    = "February",
}