I know this is a long shot, but I found something in my grandmother's note that made me curious, so perhaps someone can answer my question.
My grandmother's notes state that both my great-grandfather, Josef Vopat, and my great-grandmother, Anna Ridl Vopat held valid Bohemian Working Books. Does anyone know what she might have meant by "Bohemian Working Books?" If this is a valid record, where might one find it? My grandparents left Bohemia in approximately 1890.

Thanks in advance!
Peggy
Researching:
Vopat, Ridl, Vodraska, Bartunek, Rosengrant and Pertl