@Article{488496,
     author = "Krzysztof Piasecki, Joanna Siwek",
     title = "Behavioural present value defined as fuzzy number : a new approach",
     year =  2015,
     volume =  15(23),
     number =  2,
     journal =  Folia Oeconomica Stetinensia,
     pages =  s. 27-41,
    }