A metabibliography (or biblio-bibliography) is a bibliography of bibliographies.
While bibliographies serve the finding of relevant documents, metabibliographies serve the finding of the relevant bibliographies in which the relevant documents may be found. One might quote Patrick Wilson: "For if knowledge is power, power over knowledge is power to increase one's power; and if the stock of writings is thought of mainly as it represents a stock of knowledge, it is natural to propose treating it as a "resource" to be subjected to rational control, management and utilization."[1].
Metabibliographies are valuable for building reference collections, but usually of less interest to the average user, who rely on bibliographies selected by others.