Philippines

Ducan → Ducaur → Ducay → Ducligan → Ducol → Ducos → Ducoy → Dudiungan → Dued → Dueñas, Iloilo, Western Visayas → Duera → Duero, Bohol, Central Visayas → Duga-a → Dugaa → Dugadog, San Gabriel, La Union, Ilocos → Dugadog, San Juan, La Union, Ilocos → Dugayong, Echague, Isabela, Cagayan Valley → Dugayong, Isabela, Cagayan Valley → Dugayung, Amulung, Cagayan, Cagayan Valley → Dugayung, Cagayan, Cagayan Valley →