ISBN 4534049250 books & textbook
Shiawase ga zutto tsuzuku 12 no kodo shukan : Jibun de kaerareru 40% Ni shuchushiyo.
pub. 2012. Sonja Lyubomirsky; Mayumi Kanai; Makoto Watanabe
Nihonjitsugyoshuppansha. /2012-02-01 Tankobon Hardcover
isbn-10: 4534049250 / isbn-13: 9784534049254
