Jelaskan Rujukan dari Grace Bradley dalam bahasa melayu

Boyd, Grace Bradley and Cochran, Michael (2008) Hopalong Cassidy: An American Legend Gemstone, York, Pennsylvania;

Hopalong Cassidy's Widow, Grace Boyd, dies, sfgate.com; retrieved September 24, 2010.

Grace Bradley Boyd Tribute, americanmusicpreservation.com; accessed August 7, 2015.

Pelakon wanita Amerika Syarikat abad ke-20