The term "non-book materials" (=NBM) includes four categories of information sources drawn from the second edition of the Anglo-American Cataloguing Rules (AACR), namely:
• sound recordings;
• video recordings, including interactive video discs;
• graphic materials-photographs, illustrations, postcards and slides;
• micro-computer software, including CD-ROM
In addition, other forms covered by the term NBM are microforms -microfilms, microfiche, etc., models, wallcharts, etc. As a matter of fact, microform dates back to the year 1839 when John Benjamin Dancer, an optician and professional photographer, produced the first micro-photograph. These microforms, perhaps, offer an alternative to book storage and help in solving the space problems encountered by libraries. Commenting on the value of NBM, it was said by Leslie Gillert and Jan Wright as early as 1971 that "NBM have increased the range and means of obtaining and exploiting information for teaching, learning and research purposes, but to separate books from NBM is to divide information into false compartments. Hence, it is essential that books and non-books can be jointly identified and located to meet particular needs"