Shiyali Ramamrita Ranganathan's Reference Theory in the course of Time

This research has done in order to study Ranganathan's reference theory and its durability throughout the time .
The method of this research was the review method to study and investigate Ranganathan's works and the related literature that used his view and theory in the reference and the reference services.
Findings: The results of the study is about introducing Ranganathan' reference theory and doing research in this field. Besides, this research shows us how researchers have applied Ranganathan's view about the reference and the reference services in various fields, for example, in marketing, web design, etc. After years of their declaration by Ranganathan, they are still efficient. Studies show that the five laws of Ranganathan are still efficient in the library and new information affairs. This paper emphasizes on Ranganathan theory in the reference and the reference services along with suporting them in the field of library.