1. Die erotische Differenzierungsfähigkeit bei an der Klinefelterschen Störung leidenden Personen;Freund;Z. Psychol.,1959
2. Laboratory differential diagnosis of homo- and hetero-sexuality-an experiment with faking;Freund;Rev. Czech. Med.,1961
3. A laboratory method for diagnosing predominance of homo- or hetero-erotic interest in the male;Freund;Behav. Res Ther.,1963b
4. On the validity and reliability of the phalloplethysmographic (php) diagnosis of some sexual deviations;Freund;Rev. Czech. Med.,1958