References

1.   Amidror, Isaac, a new print-based security strategy for the protection of valuable documents and products using moire intensity profiles, Optical Security and Counterfeit Deterrence Techniques IV, Rudolf L. van Renesse, Editor, Proceedings of SPIE Vol. 4677, (2002), pp89,90

1. Associated Press, First round U.S. postage stamp on the way, Seattle Post-Intelligencer, (2011),  Retrieved 2011-01-22.
2. Baumann, Fred, what once was stamp printing is now stamp production, LINN’S STAMP NEWS, (2015)
3. Berlow, Lawrence H.,Postage Stamp, how products are made vol. 1, (2020)
4. Bozhkova, T.-Spiridonov, I. and Shterev, K., Overview of security printing types and trends in its future development, Bulgarian Chemical Communications, Volume 49, Special issue L, (2017), pp. 195 -201
5. Fan, Zhigang- Eschbach, Reiner- Wang, Shen-ge and Bala, Raja, Security Printing in Digital Age, Xerox Corporation; Webster, NY, USA, ICISH: International Conference on Imaging Science and Hardcopy, (2008), pp 8.9
6. Karanian, Matthew, "The Karabagh Story", in American Philatelist, vol. 114, No. 3, (2000), p.267
7. Kenmore Collectors Catalogue, 2010
8. Khalil, Mostafa M., The latest Security Techniques Used in Passport Design, Journal of Architecture, Arts and Humanistic Science, Article 37, Volume 4, Issue 14, (2019),  pp 58-69
9. Mallon, Thomas, Stamp: Sober Superheroes, American Heritage, Archived 2007-10-20 at Archive. today, (2006),  
10. Thomas, Anju Annie- Jeridi, Emna- Sharma, Bhoopesh Kumar- Mishra, Ved P.- Al Shamsi, Mohammad- Al Khalloufi, Mohammad, Study of Security Features of Bank Checks and Credit Cards and Decipherment, International Conference on Reliability, Infocom Technologies and Optimization (ICRITO) (Trends and Future Directions), (2018), pp 209
11. United States Postal Service / Airmail,Archived from the original on 2011-06-23, (2010), Retrieved 2010-07-31.
12. Zhao, Ruohan, Postage Stamp Design: In-house Creations for National Use, Academy of Arts & Design, Tsinghua University, (2020),

3.   Barinoff, Alex, Methods and processes used for printing postage stamps, Stamp Wiki, findyourstampsvalue.com, (2020)

6.   Bhutan, Talking Stamps" and Other World Firsts!, Sandafayre (Holdings) Ltd, (2013), Retrieved 2013

9.   Glossary of Terms, American Philatelic Society, (2017), Retrieved 7 July 2017.

14.              Pritchard, Justin , What Is Micro printing on a Check?, (2019)

15.              Rowe K. , Verge, Charles J. , Postage Stamps, The Canadian Encyclopedia, (2015) 

16.              Stolz, Hans, The Expertizing of Stamps, American Stamp Dealers Association Inc, (2019)

Electronic References

1. https://www.stampworld.com/en/articles/postage-stamp-design/
2. https://www.2-clicks-stamps.com/article/different-parts-of-postage-stamps.html
3. https://www.stampworld.com/en/articles/postage-stamp-design/