For the next edition of the ARRL Antenna Book (the 25th) I've written a section on Multi-Turn Loop Antennas for LFMF reception. It will be many months before this published and available from the ARRL. I felt the topic might be of more immediate interest to the LFMF gang and have permission to post a copy of the draft: Download Chap 22 LFMF RX loops .
The ARRL note mentions direct experimental measurements of self resonant frequency. Here is a note with more detail on the measurements and modeling comparisons between different versions of NEC: Download Loop excerpt 2