# incorrect sequence in {thebibliography}

I am very confused. I have just written an article using MikTex and used the simple bibliography for about 20 references. I use \begin{thebibliography}{99} .... \end{the....} and identify the references with \bibitem{tag1} etc. I have entered the references in the bibliography in the order that I cite them in the text using \bibitem{tag1} etc, i.e. I cite the first bibliography item first, the second next etc. Everyything works fine. I \cite{*} references in the paper totally out of sequence and everything is fine. However, if I move the first reference in the bibliography to the end of the list, so that the second item in the list becomes the first and then compile, when I check the output, everything is out of order. It is a long time since I used the bibliography, but thought that it was irrelevant what the order of the items in it were. If that isn't the case, there seems little point in it. And is it the same when using Bibtex? Have I got something wrong, or even a bug in my PC? Please put me out of my misery.

• Without seeing some actual code it hard to tell what went wrong. Could you please prepare a minimal working example (MWE) that allows others to reproduce the issue you describe? – leandriis Mar 20 '20 at 18:55
• Many thanks for the reply. I have condensed my tex file and the output to a few lines, but am having difficulty pasting the info in this box. I think, actually, the secret to the problem has been revealed by David Carlisle: if you use bibtex rather than the bib.file version, then the user dictates the order. Thanks again. – Qubus Mar 21 '20 at 9:51

If you have written the bibliography by hand then you have total control over the order, it is the order that you enter the \bibitem in the thebibliography environment.
It is normally recommended that you do not write the thebibliography environment yourself but generate it using bibtex (or biblatex+biber) in which case the generated \bibitem will be ordered according to the order specified in the bibliography style, typically alphabetic order of author names, or order of reference in your document.