Specifically, the articles reference Section 220 of the Delaware General Corporations Law, Section 1501 of the California Corporations Code and Rule 701 of the Federal Securities Act of 1933. These provisions may provide certain shareholders of some private companies the ability to obtain selected financial statements.
Links:
http://www.wsj.com/articles/startup-employees-invoke-obscure-law-to-open-up-books-1464082202
http://www.wsj.com/articles/own-startup-shares-know-your-rights-to-company-financials-1464082203