Protocol documents such as RFCs and Microsoft's Technical Documents are implementation-independent descriptions of behavior and data that define (in detail) the requirements that all implementations of a protocol must follow.

https://msdn.microsoft.com/library/jj712081

https://tools.ietf.org/html/

AUTOSAR ( https://www.autosar.org - see Tab "Standards") has a whole pool of requirements specifications (organized in moddules). SWS stands for SoftWare Specification.

have a look on the IEEE requirement specification template.

https://gephi.org/users/gephi_srs_document.pdf

check my work where you can find basic requirements for 17 quality features which I used to build a reference architecture in pervasive computing. Chapter 3 and 4 will be very useful for you

Thesis Pervasive Computing Reference Architecture from a Software E...

My page has publications which are excerpts of the thesis containing simplified details.

Please let me know if you need support or collaboration

regards

Osama Khaled

Thank you all so much

It appears that your responses takes you in two separate directions, but you like both answers. So I'm not sure as to the nature of research.

Are you studying requirements documents, and their inherent ambiguity or are you studying the structure of requirements documents?

The research study is concerned with potential ambiguities in requirements documents.

OK. Getting some types of documents will be difficult, because any companies view these documents as proprietary. Most of the research on requirements has been done in Scandinavia. One possible source is public projects. I would start locally, where your school is known. You may want to look at Agile backlogs. Simply, start contacting development organizations and expect a lot of rejection and no responses.

Good Luck