Rough classification and accuracy assessment. - Ola Ahlqvist; Johannes Keukelaar; Karim Oukbir (Int. J. Geogr. Inf. Sci., 2000)

Rough and fuzzy geographical data integration. - Ola Ahlqvist; Johannes Keukelaar; Karim Oukbir (Int. J. Geogr. Inf. Sci., 2003)