Irodov and Crotov ?
I didn't remember the name of the series and this is it. Found my favorite logarithm book:
https://mirtitles.org/2012/09/05/little-mathematics-library-...
And my memory was hazy. These are 70-80 pages rather than 20-30. They seemed like short books when I was reading them :-)
[1] https://mirtitles.org/2013/10/21/straight-lines-and-curves-v...