What's the callsign of Mom's Radio 101.9 Zamboanga?
CREATE TABLE "sbn_mom_s_radio_stations" (
  "branding" text,
  "callsign" text,
  "frequency" text,
  "power_k_w" text,
  "location" text
);
SELECT "callsign" FROM "sbn_mom_s_radio_stations" WHERE "branding"='mom''s radio 101.9 zamboanga';