  Multi-connected Universe models with space idenfication scales smaller than
the size of the observable universe produce topological images in the catalogs
of cosmic sources. In this review, we present the recent developments for the
search of the topology of the universe focusing on three dimensional methods.
We present the crystallographic method, we give a new lower bound on the size
of locally Euclidean multi-connected universe model of $3000 h^{-1} \hbox{Mpc}$
based on this method and a quasar catalog, we discuss its successes and
failures, and the attemps to generalise it. We finally introduce a new
statistical method based on a collecting correlated pair (CCP) technique.
