1 ˝RADIOTRICIAN˝ Radio Tuner Unit Manual / ˝Radiotricians˝. - London : Bernards Publishers Ltd, 1946. -(Bernards ; 52) 621.38 RADIOT radt
2 FREEDMAN, Samuel Two-way Radio / Samuel Freedman. - Chicago ; New York : Ziff-Davis Publishing Company, 1946. - 621.39 FREEDM two