Homeopathic preparations are referred to as "homeopathics"  or "remedies". Practitioners rely on two types of reference when prescribing: materia medica and repertories. A homeopathic materia medica is a collection of "drug pictures", organized alphabetically. These entries describe the symptom patterns associated with individual preparations. A homeopathic repertory is an index of disease symptoms that lists preparations associated with specific symptoms. In both cases different compilers may dispute particular inclusions.  The first symptomatic homeopathic materia medica was arranged by Hahnemann. The first homeopathic repertory was Georg Jahr's Symptomenkodex , published in German in 1835, and translated into English as the Repertory to the more Characteristic Symptoms of Materia Medica by Constantine Hering in 1838. This version was less focused on disease categories and would be the forerunner to later works by James Tyler Kent.   Repertories, in particular, may be very large.