Our chapter in the "Handbook of e-Tourism" is now published:
Wörndl W., Herzog D. (2020) Mobile Applications for e-Tourism. In: Xiang Z., Fuchs M., Gretzel U., Höpken W. (eds) Handbook of e-Tourism. Springer, Cham.
https://doi.org/10.1007/978-3-030-05324-6_17-1