“…Bacus [28], Green [29], Kruse [30], and Zack [31] have shown that a sampling density of about 0.5 p is necessary and sufficient for the analysis of erythrocyte morphology. Bacus [32], Young [33], [34], Brenner [35], Prewitt [19], Ingram [36], and Tyko [37] have also seemed to confirm this figure for leukocyte analysis. In the analysis of exfoliative cervical cytology Bartels [38] has shown through careful studies that 0.5 p sampling is necessary for accurate cell classification.…”