Need to find letters...

[Luis Lobo]

Does anybody know any site from whom i can download any one of the
following letters:

de Vries, PM Kounw, PM Othof, CG de Vries, JP Donker AJ
Bioelectrical impedance and body composition [letter]
1993 Feb 27

Smith DN
Bioelectrical impedance and body composition [letter]
1993 Feb 27

Walker M, Rodham D, Fuloher GR, Clayton B, Farrer M, Alberti KG
Bioelectrical impedance and body composition [letter]
1993 Feb 13

Thanks.