The Routledge Handbook of Heritage Language Education: From Innovation to Program Building, edited by NHLRC director Olga Kagan, co-director Maria Carreira, and associate director Claire Hitchins Chik, was published in March, 2017 as part of the Routledge Handbooks in Linguistics series. In 28 chapters the volume’s contributors analyze heritage language programs and related demographic issues in 20 languages across a variety of levels and settings in North and Latin America, Europe, Israel, Australia, New Zealand, Japan, and Cambodia.
More information on the volume can be found here: https://www.routledge.com/The-Routledge-Handbook-of-Heritage-Language-Education-From-Innovation/Kagan-Carreira-Hitchens-Chik/p/book/9781138845787