The ARRL RFI Book -- Now Shipping! -- Second Edition. Practical Cures for Radio Frequency Interference.

AC Power Interference Handbook -- New insights into the causes, effects, locating and correction of power-line and electrical interference. 3rd Edition.

Transmitter Hunting -- Radio Direction Finding Simplified

Amateur Radio Astronomy -- Explore the contributions of radio amateurs, and how to make and set up equipment to study the signals coming from space.

The RSGB Guide to EMC -- Tackle RF interference problems and understand the underlying causes.