# How to cite a CAD file?

I want to insert a CAD file as an entry in my .bib file using @misc. But it gives some errors.

! Missing $inserted. <inserted text>$


my entry:

@misc{period2,
author = {period},
title = {err_or.gds},
howpublished = {email},
year = {2018},
date = {07 August 2018},
note = {Format:gds}
}


I looked many examples like this one, which uses \RequirePackage{filecontents}. But it seems that the entry must be in the .tex file. When I put the entry in .bib file, \begin{filecontents}{mybib.bib} is not read. I prefer to put the entry in .bib file together with other normal papers, books, etc.

• I don't quite get what exactly the error is. Can you describe it a bit more, maybe including a small but complete example? And: Why do you use filecontents? As it seems to me, you could create the .bib file without problems manually. And also: Welcome to TeX.SX! – Tom Jan 24 '19 at 23:48
• Thank you for welcoming me. I do not use filecontents currently. I mentioned it before just to show what I already googled, that many suggestions use filecontents for miscellaneous entries. What I have now is only that entry @misc in .bib and that error I mentioned above. I do not know what the problem is. – Codelearner777 Jan 24 '19 at 23:52
• If I delete that @misc, the error is gone. I do not think I need a special package to use @misc or do I? Is there any wrong format in the entry? – Codelearner777 Jan 24 '19 at 23:54
• it seems the problem is I used underscore _ in the title field. I edit the post above. thanks. – Codelearner777 Jan 25 '19 at 0:27
• Have you solved your own problem? If it is solved, you should write an answer - not edit your question. I am not sure if it is of usage to others or not (question should be closed) !? – hpekristiansen Jan 25 '19 at 1:04

it seems the problem is I used underscore _ in the titlefield.
solution: There must be no underscore _ in title field.
title = {err_or.gds}, --> ERROR
title = {err-or.gds}, --> Correct
title = {error.gds}, --> Correct