Stereology Resource Center - Provides biomedical and bioscience researchers with resources for scientific measurement and analysis. Describes training, software, tissue sample analysis, and independent validation. Three-Dimensional Counting: An Accurate and Direct Method to Estimate Numbers of Cells in Sectioned Material - 1988 paper by Robert W. Williams and Pasko Rakic presenting the "counting box" method. Updated with authors' comments on their paper and on the Abercrombie's correction. International Society for Stereology - Inviting membership. Includes abstracts of journals, courses and details of related conferences. Blue Histology - A Brief Introduction to Stereology - The University of Western Australia presents an illustrated description of sampling and measurement techniques. Includes exercises in estimating volume and cell density. Explora Nova - Stereology systems including image analysis for biological research including the neurosciences, toxicology, and pharmacology. Visiopharm - Describes software, hardware, training, and custom development. Stereology Informatica - List of classes taught worldwide. Stereology Error Calculator - Calculator of standard sampling error and sampling points needed for stereological research applications. Stereologist's Blog - Explores both recent and innovative methods in stereology as well as cover interesting aspects of older issues. Stereology - Introduction to common pitfalls encountered in stereological work.