Most researchers use the concept of intellectual capital for expressing intangibles. In empirical
studies, the term intangible or intellectual capital refers to knowledge of an enterprise. The concept
of intellectual capital was attributed to John K Galbraith (1969). Porta and Olivier (2006) surveyed
for identification and classification of intellectual capital for groups of companies, while Choong
(2008) conducted an extensive analysis of various categories of definitions and classifications of
intangible assets in order to create a common body of elements. Choong (2008) has classified
intellectual capital into three main components: human capital, organizational capital (structural) and
relational capital.