LAFFÉRS, Lukáš - MELLACE, Giovanni. A note on testing instrument validity for the identification of LATE. In Empirical Economics. - Heidelberg : Physica-Verlag, 2017. ISSN 0377-7332, 2017, vol. 53, no. 3, pp. 1281-1286. Available on: https://doi.org/10.1007/s00181-016-1148-7.