The two parts are written as a single whole. Part I explains what lactate is and does; Part II covers measuring and interpreting it. Read only the second and you can run a curve but miss why it has its shape; read only the first and you understand the molecule but not the report. This bundle brings both parts together — including both glossaries — and costs less than the parts bought separately. Together: 178 pages, 28 figures and 87 scientific sources (with DOIs where available).