**Introductory Chapter: Historical and Newest Perspectives Perspectives**

**Introductory Chapter: Historical and Newest** 

DOI: 10.5772/intechopen.68917

#### Mohammed Awad Ali Khalid Mohammed Awad Ali Khalid Additional information is available at the end of the chapter

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.68917
