In what sequence one should consult the following information sources to understand about 'Referral Service' with its increasing extension and intention.
A. Library Science with a Slant to Documentation
B. Reference Service by S.R Ranganathan
C. Harrod's Librarian's Glossary and Reference Book
D. Encyclopedia of Library and Information Science
Choose the correct answer from the options given below:
1
A, B, C, D
2
B, C, D, A
3
C, D, B, A
4
D, A, B, C