Newnes short-wave manual : a treatise on the design, constructiom, operation and adjustment of short and ultra-short-wave receivers, aerials and equipment, with designs for seven short-wave receivers / F. J. Camm
Guide to utility stations
Introduction to utility dx-ing / Hans-Jürgen Karius
Novos rumos no campo das telecomunicações / Jaime de Oliveira Leandro