Earning all of Level I certifications in 30 days

I've about 3 years of Scrum experience.
By chance, a story about Ken and Scrum has come to my attention.
https://www.scrum.org/about/origins

I think it time to verify my knowledge of Scrum. (maybe ScrumBut or ScrumNot)

My journey began on June 30.
I join the community and download Scrum Guides.
Buy several books from Amazon, including:
1. Software in 30 Days by Ken Schwaber
2. A Pocket Guide (Best Practice) by Gunter Verheyen *3 (2 copies for my friends)
3. Essential Scrum by Kenneth S. Rubin

On July 5, I passed PSM 1. (88.8%)

Based on PSM 1 and years of technical background, I just studied a few articles online and attempted PSD 1 assessment.
1. PSD Glossary: https://www.scrum.org/Resources/PSD-Glossary
2. Scrum’s practices about Application Life Management https://www.scrum.org/Forums/aft/1512

My strategy is very simple and only suitable for developers.
PSD1 = PSM1 + Development skills and knowledge

On July 12, I passed PSD1. (93.8%)

The similar strategy is applied to PSPO1:
PSPO1 = PSM1 + Business knowledge
My preparing materials including:
1. The study tips of Charles Bradley http://www.scrumcrazy.com/PSPO1
2. EBMgt Guide http://www.ebmgt.org/portals/agilitypath/Documents/EBMgt_Guide_v1_CWT.p…
3. Read serials of User Stories paper by Mike Cohn. https://www.mountaingoatsoftware.com

On July 23, I passed PSPO1 (92.5%)

These are my strategy to earning all of Level I Professional Scrum certifications in 30 days.

I’m glad to meet you here.

Thanks to everybody’s input that help me a lot and excuse me for my poor English.