Informational references are available in which format? a. hard-copy c. cd-rom b. online d. all of these

d. All of these

Informational references could appear in any of these various formats. This is especially true in older, larger libraries which usually contain a variety of materials in different formats depending on the purpose of the material and the time of its publication. If you are interested in pursuing research in any particular area, it is likely that you would benefit from looking over materials in all of these different forms.

the answer is definitely d. sorry for a late response.