with Lembcke, O. W. , 2018, A fuller understanding of legal validity and soft law, in P. Westerman, J. Hage, S. Kirste & A. R. Mackor (eds.), Legal validity and soft law, Dordrecht, Springer, pp. 145-164.
with Poort, L. , 2016, Introduction: symbolic dimensions of biolaw, in B. Van Klink, B. Van Beers & L. Poort (eds.), Symbolic legislation theory and developments in biolaw, Dordrecht, Springer, pp. 1-15.
with van Beers, B. , Poort, L. , 2016, Law as a symbolic order: some concluding remarks, in B. Van Klink, B. Van Beers & L. Poort (eds.), Symbolic legislation theory and developments in biolaw, Dordrecht, Springer, pp. 289-297.
, 2016, Symbolic legislation: an essentially political concept, in B. Van Klink, B. Van Beers & L. Poort (eds.), Symbolic legislation theory and developments in biolaw, Dordrecht, Springer, pp. 19-35.
with van Beers, B. , Poort, L. (eds) , 2016a, Symbolic legislation theory and developments in biolaw, Springer, Dordrecht.