The chemistry laboratory: Development of average, fixed, and variable costs for incorporation into a management control system
Medical Care
http://www.ncbi.nlm.nih.gov/pubmed/?term=The%20chemistry%20laboratory%3A%20Development%20of%20average%2C%20fixed%2C%20and%20variable%20costs%20for%20incorporation%20into%20a%20management%20control%20system.