Daniel W. Tholen. Impact of international standards and initiatives on
proficiency testing for medical laboratories. Accreditation and Quality
Assurance: Journal for Quality, Comparability and Reliability in Chemical
Measurement, Volume 9, Numbers 11-12(October 2004), pp. 653-656,
<http://ejournals.ebsco.com/direct.asp?ArticleID=DLL026FXENG4UN1K21MG>

Adriaan M. H. van der Veen, Theo L. Hafkenscheid. Harmonisation of
proficiency testing schemes. Accreditation and Quality Assurance: Journal
for Quality, Comparability and Reliability in Chemical Measurement, Volume
9, Numbers 11-12(October 2004), pp. 657-661,
<http://ejournals.ebsco.com/direct.asp?ArticleID=XF7M1Y02M69B0C6K7F6P>

Christine Walton. Bioterrorism: impact on external quality assessment
service delivery. Accreditation and Quality Assurance: Journal for Quality,
Comparability and Reliability in Chemical Measurement, Volume 9, Numbers
11-12(October 2004), pp. 662-665,
<http://ejournals.ebsco.com/direct.asp?ArticleID=37HEB4Q1T8LX4JDN88M5>

Michael Koch. Regulatory aspects of proficiency testing: experience from the
water sector. Accreditation and Quality Assurance: Journal for Quality,
Comparability and Reliability in Chemical Measurement, Volume 9, Numbers
11-12(October 2004), pp. 684-687,
<http://ejournals.ebsco.com/direct.asp?ArticleID=458DVKY8GCYVJ3PY0GHK>

Ulf Örnemark, Harald Fostel, Rolf Straub, Johannes van de Kreeke. Policies,
requirements and surveys concerning frequency for participation in
proficiency testing schemes. Accreditation and Quality Assurance: Journal
for Quality, Comparability and Reliability in Chemical Measurement, Volume
9, Numbers 11-12(October 2004), pp. 729-732,
<http://ejournals.ebsco.com/direct.asp?ArticleID=2CM3VDUM1RGVDDF7DEYH>