TY  - CHAP
ID  - Kruse1989
T1  - On Calculating the Covariance in the Presence of Vague Data
A1  - Kruse, Rudolf
A1  - Meyer, K. D.
ED  - Janko, W. H.
ED  - Roubens, M.
ED  - Zimmermann, Hans-Jürgen
T3  - Progress in Fuzzy Sets and Systems
Y1  - 1989
PB  - Kluwer
AD  - Amsterdam, Netherlands
ER  -