@article {Thomson1987a, title = {Patriarchs Euthymius of Tarnovo and Philotheus of Consatantinople and Liturgical Reforms in Fourteenth Century Bulgaria}, journal = {Palaeobulgarica / Старобългаристика}, volume = {11}, year = {1987}, pages = {116{\textendash}119}, author = {Thomson, Francis J.} }