Shin, Sooyoung Kim; Lee, Soo In: 'Efficient complexity reduction technique in trellis decoding algorithm', Electronics Letters, 1999, 35, (1), p. 16-17, DOI: 10.1049/el:19990081 IET Digital Library, https://digital-library.theiet.org/;jsessionid=18psj5u1ncqob.x-iet-live-01content/journals/10.1049/el_19990081