more recent editions of Talmud Bavli. A page number in the Vilna Talmud refers to a double-sided page, known as a daf, or folio in English; each daf has two amudim labeled and , sides A and B (recto and verso). The convention of referencing by daf is relatively recent and dates from the early Talmud printings of the 17th century, though the actual pagination goes back to the Bomberg edition. Earlier rabbinic literature generally refers to the tractate or chapters within a tractate (e.g. Berachot Chapter 1, ). It sometimes also refers to the specific Mishnah in that chapter, where "Mishnah" is replaced with "Halakha", here meaning route, to "direct" the reader to the entry in the Gemara corresponding to that Mishna (e.g. Berachot Chapter 1 Halakha 1, , would refer to the first Mishnah of the first chapter in Tractate Berachot, and its corresponding entry in the Gemara). However, this form is nowadays more commonly (though not exclusively) used when referring to the Jerusalem Talmud. Nowadays, reference is usually made in format [Tractate daf a/b] (e.g. Berachot 23b, ). Increasingly, the symbols "." and ":" are used to indicate Recto and Verso, respectively (thus, e.g. Berachot 23:, ). These references always refer to the pagination of the Vilna Talmud. Critical editions The text of the Vilna editions is considered by scholars not to be uniformly reliable, and there have been a number of attempts to collate textual variants. In the late 19th century, Nathan Rabinowitz published a series of volumes called Dikduke Soferim showing textual variants from early manuscripts and printings. In 1960, work started on a new edition under the name of Gemara Shelemah (complete Gemara) under the editorship of Menachem Mendel Kasher: only the volume on the first part of tractate Pesachim appeared before the project was interrupted by his death. This edition contained a comprehensive set of textual variants and a few selected commentaries. Some thirteen volumes have been published by the Institute for the Complete Israeli Talmud (a division of Yad Harav Herzog), on lines similar to Rabinowitz, containing the text and a comprehensive set of textual variants (from manuscripts, early prints and citations in secondary literature) but no commentaries. There have been critical editions of particular tractates (e.g. Henry Malter's edition of Ta'anit), but there is no modern critical edition of the whole Talmud. Modern editions such as those of the Oz ve-Hadar