Verily, know, that the letter of 'Abdu'l-Bahá is a hidden mystery and concealed fact; no one is informed of its greatness and importance at these times. But in the course of time and future centuries, the signs thereof will be made manifest, the lights thereof will dawn. The fragrance thereof will be diffused and the greatness, the importance thereof will be known. The truth I say unto thee, that each leaflet from 'Abdu'l-Bahá will be a widespread Book; nay, rather a glistening Gem on the Glorious Crown. Know thou Its value and hold great Its station. [CBN No 19 April 1951 p9]

Try also a shorter date like 1951-04-0 or 1951-04

try also the main Chronology — 1951-04-00 or 1951-04-0 or 1951-04