Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by H Van PraagfiledCriticalH Van Praag
Priority to BE590287ApriorityCriticalpatent/BE590287A/fr
Publication of BE590287ApublicationCriticalpatent/BE590287A/fr