1. Preparation of bloodspot TSH-calibrators—a problem?;Elvers,1994
2. 1994 EQA Surveys for determining TSH from dried blood on filter paper;German Society for Clinical Chemistry,1995
3. Impact of differences in the filter paper matrix on outcomes of PKU testing;Adam;Infant Screening,1994
4. An evaluation of different filter paper lots used during the last five years;Jensen,1984
5. Calibration and control materials for neonatal hypothyroid screening programs: proposed guideline;National Committee for Clinical Laboratory Standards (NCCLS),1983