Fryslân or Friesland Court Records
Seeing that in Fryslân the Frisian language is spoken, you may have a difficult time reading the court records. The Family History Library in Salt Lake City, Utah has some fo the court records and you can find them in their catalog under Friesland as well as under individual towns, which then will give you the book call number or the film number.
There are, however, also websites with a wide variety of records. Again, some may be in in Frisian, but often the cases are alphabetised, see:            registry inheritance taxes To search this web-site you go to 'genealogy' --> 'inheritance tax'