Algebraic & Geometric Topology Volume 5, issue 4 (2005)

1	D K Biss, The topological fundamental group and generalized covering spaces, Topology Appl. 124 (2002) 355 MR1930651
2	P Fabel, Topological fundamental groups can distinguish spaces with isomorphic homotopy groups, Topology Proc. 30 (2006) 187 MR2280667
3	J W Morgan, I Morrison, A van Kampen theorem for weak joins, Proc. London Math. Soc. $(3)$ 53 (1986) 562 MR868459