Laboratory Reference Ranges-- from the American Board of Internal Medicine (ABIM), January 2024.
Normal Laboratory Values-- from the Merck Manual, Professional Version. The values for "...blood, urine, cerebrospinal fluid (CSF), stool, and other fluids (e.g, gastric acid) and commonly used panels are included. NOTE: The reference values provided in these tables should be used as guidelines only..."
The full statement about the lab values is available on the same page.