An objective evaluation of a scientific activity is required to reduce partialities and mistakes, thus allowing a more reliable judgement. Therefore, the role of scientific literature, as the most direct expression of research activity, is increasing; for a better evaluation, bibliometric and bibliographic indicators have been developed. Bibliometric indicators are based upon citation, which is a meter of the use the international scientific community makes of research results, once published. Besides the number of publications, the most important bibliometric indicators are the number of citations, the impact factor, the immediacy index, the half-life index. Bibliographic indicators are the reference of the journal or the paper by a given author, in important bibliographies of international influence. Being the evaluation by means of these indicators extremely complex, there is a need for a homogeneous regulation of the activity, at an institutional level. The presence of experts in scientometrics is also advisable, since they can provide evaluation profiles on demand, with the support of modern documentation centres. In sum, after describing bibliometric and bibliographic indicators, emphasis is put on their utility and the role they play in support of experts' judgement for a more precise evaluation of a scientific activity.