It seems that a few journals restrict the number of authors to three. I think that you should avoid such journals, because such a restriction does not match reality. Many publications have more than three authors. In high-energy physics, there are even papers with several thousand authors.

Dear Faisal Nasser

I am afraid that your question translated in English is not reflecting the point of your question. I ran your question you asked in Arabic through Google translate and I think your question is more:

If I am the fourth researcher in scientific research, how many points do I get for academic promotion with appreciation?

This is not that straightforward to answer and depends on your university/organization/country. In my country I think you can summarize it as follow:

-For a PhD (depends on the discipline/field of science as well) you need a number of publications as first author (since you performed the research)

-If you have a number of papers as second, third or more co-author then this is nice to put on your CV but does not attribute much to the PhD requirements (although sometimes there are papers where the first and second author contributed equally and in this case it counts fully as published for your PhD thesis)

-If you want to make your papers count for a possible promotion (towards assistant professor, associate professor etc.) then you are counted as research supervisor and then automatically your are not always first author and then the number of published papers will count in some way

-In general (regardless in which tenure track type of evaluation one might be) every paper (as first author or as co-author) is indicative for your academic production (and ability to collaborate and participate in a multidisciplinary project) and therefor should be counted somehow

Since every paper list their (co-)authors differently, some use ‘simply’ an alphabetic order, others follow a sequence of the extent everyone contributed to the research etc., it is/would be somewhat ridiculous to come up with a number. So, saying the third co-author counts more than a fourth is in general terms a ridiculous rule.

Best regards.

There's no universal requirement for the number of researchers in scientific research published in journals. Research can be conducted by individuals or teams of varying sizes, depending on the complexity of the study, available resources, and disciplinary norms. Journals typically focus more on the quality, rigor, and significance of the research rather than the number of researchers involved. However, some journals may have specific authorship guidelines that recommend or require certain criteria for inclusion as an author.