Analysis of information sources in references of the Wikipedia article "List of Scottish football champions" in English language version.
1988: Celtic celebrate the centenary season (1987/88) by winning the first "double" in 11 years. The accomplishment marks the 35th league title, and the 28th Scottish Cup.
In 1948–49, Rangers became the first team to win the League, the Scottish Cup, and the League Cup in one season. It was the first glorious treble in Scottish football.
1988: Celtic celebrate the centenary season (1987/88) by winning the first "double" in 11 years. The accomplishment marks the 35th league title, and the 28th Scottish Cup.
In 1948–49, Rangers became the first team to win the League, the Scottish Cup, and the League Cup in one season. It was the first glorious treble in Scottish football.