In continuation of the earlier studies on bibliometric indicators, communicated in Parts I and II of this series, the present communication sets out to study the frequency-distribution of co-authorship pattern of Pakistani journals in detail. The two initially selected journals are Proceedings of the Pakistan Academy of Sciences (PPAS) and Pakistan Journal of Scientific and Industrial Research (PJSIR). The present results not only amplify the previous findings, but the graphs drawn lead to the conclusion that there is a definite relationship of author-to-paper ratio with large frequencies at values of 3,6 and 9. As a corollary to this finding, it would follow that certain group-sizes have optimum per-capita research outputs; it is evident that number 3 seems to be basic in pointing to the smallest viable unit for high research output. Probably, multiples of 2 and 3 may form important combinations of this basic unit. Further studies to elaborate these points are in hand.