Burke's Genealogical & Heraldic Guide to the Peerage, @ p 1913, No title, does not mention parents
The cited information was published by Burke's Peerage, London, 1949 (Ref: p 1913, No title, does not mention parents) The author/originator was Burke's Peerage.
Source Notes
TITL Burke's Genealogical & Heraldic Guide to the Peerage,
Baronetage & KnightageABBR Burke's Peerage