William Boyes
and Hang Sheng Cheng
and Guillermo Ortiz
and Nicholas Hope
and H. Robert HellerJournal of International Money and Finance5
S161--S175
(1986)
Iber{\^e} L. Caldas
and Maria Vittoria A. P. Heller
and Raul M. Castro
and Elton C. SilvaPhysica A: Statistical and Theoretical Physics257
341--346
(1998)