1. M. Chas and D. Sullivan “String Topology” GT/ 9911159. Accepted by Annals of Mathematics.
2. A. Voronov “Notes on Universal Algebra”. See author’s web page. To appear in proceedings of Stony Brook conference on “Graphs and Patterns in Mathematics and Physics”, June 2001.
3. E. Getzler “Operads and moduli spaces of genus zero Riemann surfaces”. In:The Moduli Spaces of Curves ed. by R. Dijkgraaf, C. Faber, G. van der Geer Progress in Math, vol.129 Birkhauser 1995, 199–230.
4. Wee Liang Gan “Koszul duality for dioperads” preprint University of Chicago 2002. QA/0201074
5. Yuri I. Manin “Frobenius Manifolds, Quantum cohomology and Moduli spaces”. AMS Colloquium Publications Vol.47.