Philosophical transactions. Series A, Mathematical, physical, and engineering sciences Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 378 (2165) Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, Royal Society, The, 2020, 378 (2165), pp.20180425. ⟨10.1098/rsta.2018.0425⟩