There have been differences of opinion between researchers concerning wire strings on the citole. Other earlier instruments include the medieval European citole and the Greek and Byzantine pandura. The Italian citole, known there as "cetra", eventually became the cittern. The Ducal Palace Studiolo Cittern/Citole shows cuts in the neck in place of frets. One Cantigas de Santa Maria citole has four frets, the others five. This latter type is found in the Cantigas de Santa Maria, the St. Savin citole. On the Parma citole, it is positioned in the center of the soundboard. Another early image Wright mentions is a holly-leaf citole in sculpture at Carboeiro, c. 1238-1266. The Robert de Lisle Psalter citole (deep neck with thumbhole) is depicted with five frets. He characterized this citole as having a "spade" shape. This line entered Europe, becoming the plucked fiddles (vielle, viola, giga, citole). Citole players have also been shown holding their instruments vertically. An example, with a less-prominent waist is the Robert de Lisle citole. One researcher, Thurston Dart, stated in 1948, that the citole was strung with wire strings.