In the present project we will focus on critical behaviour of Cu3(pyrazine)[W(CN)8]2 revealing magnetic phase transition at Tc=43 K. The findings will be compared to those already obtained for the structurally related compound Cu7[W(CN)8]4 with magnetic phase transition at Tc=40K. Zero field measurements are proposed with a special attention to the vicinity of the phase transition. Moreover, longitudinal and transverse field scans for a few temperatures below and above the transition, respectively, are suggested to get insight into spin relaxation dynamics and spin correlations. In view of our latest research, noticeable differences in the values of critical exponents of these two samples are expected.