The grammars of the Main Series A are designed as “reference grammars”, which mostly only deal with the phonology and morphology, and sometimes with the syntax as well. They provide information principally on confirmed grammatical findings, but also point to gaps and controversies in the research, both with copious references to the literature, thus allowing the reader to penetrate the material more deeply. The “Summaries” in Series C restrict this information to the minimum necessary. The Supplementary Series B presents books dealing with subjects from grammar, language history and ancillary disciplines.