  We study the finite temperature-density phase diagram of an attractive
fermionic system that supports two-body (dimer) and three-body (trimer) bound
states in free space. Using interactions characteristic for nuclear systems, we
obtain the critical temperature T_c2 for the superfluid phase transition and
the limiting temperature T_c3 for the extinction of trimers. The phase diagram
features a Cooper-pair condensate in the high-density, low-temperature domain
which, with decreasing density, crosses over to a Bose condensate of strongly
bound dimers. The high-temperature, low-density domain is populated by trimers
whose binding energy decreases toward the density-temperature domain occupied
by the superfluid and vanishes at a critical temperature T_c3 > T_c2.
