Borrowing from Rob-Keller: The best and most easy way to create a DOI for a paper of a journal that don't assign DOI number or chapters of previously published books without a DOI etc. is Zenodo: https://zenodo.org/
It was given earlier but these days it seems that due to some error or change in policy they are giving URL only to anyone. you can check the links of other research paper. contact elsveir.com or ssrn for reasons.