H. BERTHOUD : Orologio gioiello anni '20 - Asta Asta di orologi da polso, da tasca e pendole - Associazione Nazionale - Case d'Asta italiane
Silver Berthoud gentlemen pocket watch (Switzerland, beginning of 19th century) - Auction Fine Jewels and Watches - I - Maison Bibelot - Casa d'Aste Firenze - Milano
Perret & Berthoud orologio da tasca in oro - Gioielli, Orologi e Argenti – Asta 140 - Minerva Auctions
مسكن كشك الإشارة ملك من القرص احد الأمرين berthoud orologi - stimulkz.com
Chronométrie Ferdinand Berthoud - Exceptional timepieces - Swiss made