Their sources are unofficial and unreliable printed works of reference, which are far from comprehensive and contain numerous errors and omissions. There is no such thing as a Coat of Arms for a surname, as Coats of Arms belong only to the original grantees and their descendants in the male line. Coats of Arms do not belong to surnames. There is no such thing as a 'coat of arms for a surname'. Many people of the same surname will often be entitled to completely different coats of arms, and many of that surname will be entitled to no coat of arms.
Coats of arms belong to individuals.
For any person to have a right to a coat of arms they must either have had it granted to them or be descended in the legitimate male line from a person to whom arms were granted or confirmed in the past. The College of Arms is the official repository of the coats of arms and pedigrees of English, Welsh, Northern Irish and Commonwealth families and their descendants. Its records also include official copies of the records of Ulster King of Arms the originals of which remain in Dublin. The officers of the College, known as heralds, specialize in genealogical and heraldic work for their respective clients. Coats of arms have been and still are granted by Letters Patent from the senior heralds, the Kings of Arms.