Retrieves reference values for Myocardial Blood Flow (MBF) based on the specified parameter and author.

Key Logic:

• Optional Gender: The gender parameter is optional.

  • If you provide a gender (e.g., male), the API will search for gender-specific data.
  • If you omit the gender parameter, the API will search for the overall, non-gender-specific value.
  • Note: Not all authors have provided gender-specific data.

• Data Availability: Not every author has published data for every parameter. If you request a combination that does not exist in the data source (e.g., gender-specific data from an author who only published overall values), the API will return a 404 Not Found error.