 Römer wrote important works on Lithuanian history and on law, such as the 1908 book "Lietuva.Studija apie lietuvių tautos atgimimą" and the 1928 book "Die Verfassungsreform Litauens im Jahre 1928".He is considered to be one of the most prominent Lithuanian jurists, the progenitor, first lector and one of the most prominent authors of interwar Lithuanian constitutional law.