  In this paper the next attempt is made to clarify the nature of the Euclidean
behavior of the boundary in the angular size-redshift cosmological test. It is
shown experimentally that this can be explained by the selection determined by
anisotropic morphology and anisotropic radiation of extended radio sources. A
catalogue of extended radio sources with minimal flux densities of about 0.01
Jy at 1.4 GHz was compiled for conducting the test. Without the assumption of
their size evolution, the agreement between the experiment and calculation was
obtained both in the Lambda CDM model (Omega_m=0.27 , Omega_v=0.73.) and the
Friedman model (Omega = 0.1 ).
