www.pteridines.org
            Pteridines, Journal of ISP

 www.pteridines.sk
            Pteridines, Journal of ISP, down-load pdf-files

www.i-med.ac.at  
            Innsbruck Medical University

fld.i-med.ac.at/fld-prod/public/mylogin.cgi  
            publication output, Innsbruck Medical University

www.i-med.ac.at/imcbc/molecularcellbiologyfolder/molcellbiol.html
            Division of Biological Chemistry, Innsbruck Medical University

www.physiological-chemistry.at/IMCPL/Forschung/pteridine.php
            Institute of Physiological Chemistry, Medical University of Graz

www.bh4.org 
            BH4 - Tetrahydrobiopterin Homepage

www.schircks.com
            Schircks Laboratories, Home of Pteridines

www.ncbi.nlm.nih.gov  
            PubMed, National Library of Medicine

www.brahms.de
            BRAHMS Company, Hennigsdorf/Berlin, Germany, Neopterin Immunoassay Supplier

www.ibl-hamburg.com
            Immunobiological Laboratories, Hamburg, Germany, Neopterin Immunoassay Supplier

www.concile.de
            Concile GmbH, Freiburg, Germany, Neopterin Immunoassay Supplier

www.ksbbiotech.com
            Shenzen Kang shen Bao Bio-Technology Co. Shenzen, China, Neopterin Immunoassay Supplier