The Harvard Business Review website allows non-registered users to see 5 articles per month. Registered users (free with sign up) can view 15 articles per month. Subscribers pay a fee and have unlimited access to all HBR articles on the website.
The website contains daily content that cannot be found in Business Source Complete. HBR once called these blog posts, but the website refers to them as articles. If you cannot find an HBR article in the libraries database it may be one of these daily content articles. To find these search under the "latest" category.
You may find some records in the Business Source Complete Database for Harvard Business Review Case Studies. If the full text of the case study is not available then the library has not purchased the content. Case studies may be purchased from the University of Colorado Book Store or from the Harvard Business Review store.