In addition to PhD Research, you may also want to check out websites like Upwork or Freelancer, where you can hire freelance writers who specialize in scientific writing. Another option is to look into academic editing and proofreading services like Editage or Enago, which can help with formatting, grammar, and overall clarity of your paper. And don't forget to check with your university or research institution, as they may have scientific writing services available for their students and faculty