1 1/2 ounces gin
1/4 ounce dry vermouth
1/4 ounce sweet vermouth
2 dashes triple sec
2 dashes lemon juice
1 dash Angostura Bitters
Shake with ice and strain into a cocktail glass
Source: "The Savoy Cocktail Book" (1930) by Harry Craddock

You can sometimes find this recipe going by the name "Periodista", which is Spanish for "Journalist". However, the "real" Periodista is a different drink all together.