- Some US universities (and a few European universities and research institutes) have organized internship programs. You apply to the program, not an individual lab. Applications for such programs often have to be made on a specific form. The defined application processes, outlined in their prospectus, must be accurately followed. I have a tentative list of some good programs.
- Most European and American universities have no internship program. You apply to individual laboratories. Such applications should consist of:
- a cover letter,
- a CV,
- a transcript (copy is enough), and
- a sheet with the addresses of two or three referees (professors who will write a letter of recommendation for you).
- If you want to apply to a company, the application process is usually also requires cover letter, CV, transcript, and referees' addresses. It always pasy to know someone inside the company to whom the materials can be addressed.