Tito Flavio Vespasiano Frasi e Citazioni
Tito Flavio Vespasiano: Frasi in inglese
Chmaber's Dictionary of Quotations, p. 879-880, attributed "His son Titus had objected to a tax on the contents of the city's urinals (used by fullers). Quoted in Suetonius Vespasian, chapter 23.