1. The use of digital circuits in data transmission;van Gerwen;Philips Technical Review,1969
2. Data modems with integrated digital filters and modulators;van Gerwen;IEEE Trans. on Communication Technology,1970
3. Digital generation of linearly modulated data waveforms;Snijders;IEEE Trans. on Communication Technology,1975
4. Balanced modulation and the exclusive-OR function;Rey,1970