OTD in 1987, Athletics' Mark McGwire Tied Record with 5 homers in

1998 Major League Baseball home run record chase - Wikipedia

1998 Major League Baseball home run record chase - Wikipedia

Mark McGwire belts a 533-foot home runs on this day in history

Baseball; McGwire Breaks Rookie Homer Record - The New York Times

OTD in 1987, Athletics' Mark McGwire Tied Record with 5 homers in 2 Days in Cleveland - Sports Illustrated Oakland Athletics News, Analysis and More

The Most Expensive Mark McGwire Cards of All-Time

MARK MCGWIRE 2018 Topps Archives 1981 Design #275 Athletics

Throwback Thursday: Remembering Mark McGwire's 1987 Rookie Season - Athletics Nation

The Twins Almanac for May

Mark McGwire '87 Record Breakers - 1988 Topps #3 Oakland A's Error

MLB's 500 home run club

Oakland A's news: Doubts about Stockton as A's alternate training site - Athletics Nation