Background: As a result, in 1979, Sony and Philips set up a joint task force of engineers to design a new digital audio disc. Led by engineers Kees Schouhamer Immink and Toshitada Doi, the research pushed forward laser and optical disc technology. After a year of experimentation and discussion, the task force produced the Red Book CD-DA standard. First published in 1980, the standard was formally adopted by the IEC as an international standard in 1987, with various amendments becoming part of the standard in 1996.
Question: Who headed the 1979 Sony and Philips digital audio disc task force?
Answer:<extra_id_0>.
<extra_id_0> Kees Schouhamer Immink and Toshitada Doi<extra_id_1>