%0 Journal Article %A Nagasawa, Masao %A Tanaka, Hiroshi %T The principle of variation for relativistic quantum particles %J Séminaire de probabilités %D 2001 %P 1-27 %V 35 %I Springer - Lecture Notes in Mathematics %U https://www.numdam.org/item/SPS_2001__35__1_0/ %G en %F SPS_2001__35__1_0