  We study the behavior of weakly bound clusters and their relation to the
well-known three-body Efimov states. We adopt a model to describe universal
behavior of strongly interacting bosonic systems, and we test its validity by
reproducing predictions of three- and four-body universal states. Then, we
extend our study to larger systems and identify a series of universal cluster
states that can be qualitatively interpreted as adding one particle at a time
to an Efimov trimer. The properties of these cluster states and their
experimental signatures are discussed.
