@article(aschieriB10,
 author       = "Federico Aschieri and Stefano Berardi",
 year         = "2010",
 title        = "Interactive Learning-Based Realizability for {H}eyting Arithmetic with {${\mathsf {EM}_1}$}",
 journal      = "Logical Methods in Computer Science",
 volume       = "6",
 number       = "3",
 doi          = "10.2168/LMCS-6(3:19)2010",
)
@inproceedings(berardidL08,
 author       = "Stefano Berardi and Ugo de'Liguoro",
 year         = "2008",
 title        = "A Calculus of Realizers for {${\mathsf {EM}_1}$} Arithmetic (Extended Abstract)",
 booktitle    = "CSL",
 pages        = "215--229",
 doi          = "10.1007/978-3-540-87531-4\_17",
)
@phdthesis(birolo13thesis,
 author       = "Giovanni Birolo",
 year         = "2013",
 title        = "Interactive Realizability, Monads and Witness Extraction",
 school       = "University of Turin",
 url          = "http://arxiv.org/abs/1304.4091",
)
@book(troelstraVD88,
 author       = "A.S. Troelstra and D. van Dalen",
 year         = "1988",
 title        = "Constructivism in Mathematics",
 series       = "Studies in Logic and the Foundations of Mathematics",
 publisher    = "Elsevier Science",
 url          = "http://books.google.it/books?id=-tc2qp0-2bsC",
)