When I originally discovered the book ชื่อจังหวัด อำเภอ/กิ่งอำเภอ ตำบล เขต และแขวง ไทย-อังกฤษ (Thai-English transcription of changwat, amphoe, king amphoe, tambon, khet, and khwang approved by the Royal Institute, ISBN 9789747857047) as an eBook at the website of the Department of Provincial Administration (DOPA), it was only available as four PDF files, which made it quite some work to go through all the 7000+ subdistricts and check and correct the names in my spreadsheet.
I was now recently browsing through the announcements at the website amphoeyim.com (District Smile), another website from the Ministry of Interior around the district administration, just to look if there anything new to me. It also had the same publication online there, however once I downloaded it to my surprise it was two Excel files and two PDF, the actual data now in much easier readable form. Funnily, the original source at DOPA had also changed since I last checked it and also contains the two Excel sheets instead of the PDF with the tables.
As the XLS files are last changed in 2007, they obviously cannot include fixes to the mistakes I noted back then - see my own sheet with the dubious or wrong transcriptions - nor contain the new subdistricts created in Bangkok last year.
I don't know if there will be any new edition of the book, yet even better than such a reference book would be an online list continuously updated, for example adding the transcription into the geocode list.
By the way, if anyone can get me the paper version of that book it'd be a nice addition to my library, though just for collection. If I recall correctly, I read that the book was mostly distributed to libraries, including the local ones in each province - maybe wasn't even sold commercially.