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 Gerardus Geertruud De VaalfiledCriticalGerardus Geertruud De Vaal
Publication of ZA989354BpublicationCriticalpatent/ZA989354B/en