Table: indigenous_radio_stations
Columns: call_sign
launched
transmitting_from
coverage
languages
frequency

Question: What is the frequency of the station that was launched on 21 August 1994?
SQL: SELECT "frequency" FROM indigenous_radio_stations WHERE "launched" = '21 august 1994'

Question: What is the launched date of the station in cora huichol tepehuano nahuatl language?
SQL: SELECT "launched" FROM indigenous_radio_stations WHERE "languages" = 'cora huichol tepehuano nahuatl'

Question: Where is the station with a coverage of yucatán quintana roo campeche transmitting from?
SQL: SELECT "transmitting_from" FROM indigenous_radio_stations WHERE "coverage" = 'yucatán quintana roo campeche'

Question: What is the frequency of the station with a coverage of oaxaca guerrero puebla?
SQL: SELECT "frequency" FROM indigenous_radio_stations WHERE "coverage" = 'oaxaca guerrero puebla'

Question: Where is the station that was launched on 17 July 1997 transmitting from?
SQL: SELECT "transmitting_from" FROM indigenous_radio_stations WHERE "launched" = '17 july 1997'

Question: What is the coverage of the station that was launched on 22 January 1996?
SQL: SELECT "coverage" FROM indigenous_radio_stations WHERE "launched" = '22 january 1996'