[1] DEPT TRADE & IND,LAB GOVT CHEM,CORNWALL HOUSE,STAMFORD ST,LONDON SE1 9NQ,ENGLAND
[2] US DEPT COMMERCE,NBS,ORG CHEM DIV,CLIN PROGRAM,WASHINGTON,DC 20234
[3] CTR MED PREVENT,2 AVE DOYEN JACQUES PARISAT,VANDOEUVRE 54,FRANCE
[4] DE GAMLES BY,DEPT CLIN CHEM,GERIATRIC UNIT,NORRE ALLE 41,DK-2200 COPENHAGEN N,DENMARK
[5] NORTHWICK PK HOSP,DEPT CLIN CHEM,WATFORD RD,HARROW HA1 3UJ,MIDDLESEX,ENGLAND
[6] CLIN RES CTR,DIV CLIN CHEM,WATFORD RD,HARROW HA1 3UJ,MIDDLESEX,ENGLAND
[7] INST MED & VET SCI,DIV CLIN CHEM,FROME RD,ADELAIDE,AUSTRALIA
[8] NIH,CLIN PATHOL DEPT,CLIN CHEM SERV,BETHESDA,MD 20014
[9] HOSP SICK CHILDREN,555 UNIV AVE,TORONTO M5G 1X8,ONTARIO,CANADA
[10] NAT PHYS LAB,DIV CHEM STAND,TEDDINGTON TW11 0LW,MIDDLESEX,ENGLAND
[11] RIJKS INST VOLKSGEZONDHEID,INT FED CLIN CHEM,COMMITTEE STAND,POB 1,BILTHOVEN,NETHERLANDS
[12] UNIV HELSINKI,MEILHAHTI HOSP,DEPT CLIN CHEM,HELSINKI 29,FINLAND
[13] NATL INST BIOL STAND & CONTROL,HOLLY HILL,HAMPSTEAD,LONDON NW3 6RB,ENGLAND
[14] WHO,CH-1211 GENEVA 27,SWITZERLAND
[15] COMMISSION EUROPEAN COMMUN,BRUSSELS,BELGIUM
[16] DEPT HEW,CTR DIS CONTROL,CLIN CHEM BRANCH,ATLANTA,GA 30333
[17] EURATOM,I-21020 ISPRA,ITALY
[18] HARTFORD HOSP,INT FED CLIN CHEM,EXPERT PANEL ENZYMES,HARTFORD,CT 06115
[19] UNIV ORANGE FREE STATE,DEPT CHEM PATHOL,POB 339,BLOEMFONTEIN 9300,SOUTH AFRICA
[20] US DEPT COMMERCE,NBS,OFF STAND REFER MAT,WASHINGTON,DC 20234
[21] GEORGETOWN UNIV HOSP,3800 RESERVOIR RD NW,WASHINGTON,DC 20007
[22] MED HSCH HANOVER,INST KLIN CHEM,COMMITTEE STAND INT FED CLIN CHEM,KARL WIECHERT ALLEE 9,3 HANOVER,FED REP GER