↑ R. Moses b. Maimon Responsa, ed. Jehoshua Blau, Rubin Mass Ltd. Publishers, Jerusalem 1989, vol. 1, responsum # 134
↑ Mishnah - with a Commentary of Rabbi Moses ben Maimon (ed. Yosef Qafih), vol. 1, Mossad Harav Kook: Jerusalem 1963, s.v. Berakhot 1:5 (p. 33); Questions and Responsa of Rabbi Moses ben Maimon (ed. Joshua Blau), vol. 1, Rubin Mass publishers: Jerusalem 1989, responsum # 134 (pp. 251–255); Yaakov de Castro, `Erekh Leḥem (Orach Chaim §233:2)
↑ Mishnah - with a Commentary of Rabbi Moses ben Maimon (ed. Yosef Qafih), vol. 1, Mossad Harav Kook: Jerusalem 1963, s.v. Berakhot 1:5 (p. 33), who wrote: "Be apprised that all of the hours that are mentioned throughout all the Mishnah are none other than relative hours, and the word relative has the connotation of those hours wherein there are twelve in the daytime, as also at night."
↑ Questions and Responsa of Rabbi Moses ben Maimon (ed. Joshua Blau), vol. 1, Rubin Mass publishers: Jerusalem 1989, responsum # 134 (p. 252)
↑ Magen Avraham §58:1, §233:3 of R. Avraham Gombiner; Maimonides' commentary on Mishnah Megillah 2:4; the Responsa Terumat HaDeshen, responsum # 1 of R. Israel Isserlein; the Levush §267 of R. Mordecai Yoffe; Minchat Kohen (Mevoh Shemesh 2:6) of R. Abraham Cohen Pimentel, in the name of Tosefot Ha-Ramban (Nachmanides) and R. Shlomo ben Aderet (Rashba); Bayit Chadash §431 of R. Joel Sirkis; Turei Zahav §433 of R. David HaLevi Segal; Pri Chadash §433 of R. Hezekiah da Silva; Eliyahu Rabbah 58:2 of R. Elijah Spira; Mizbe’ach Adamah 4a of R. Mordechai Chaim Meyuchas; Mikra'ei Kodesh 158b by R. Baruch Gigi; Mateh Yehuda §433 of R. Yehudah Ayash; the Responsa Hayim Sha'al 2:38 (70) of R. Chaim Yosef David Azulai; Tov Ayin 18:38 of R. Alter Yechiel Naiman; Chayei Adam 21:3, 27:1 of R. Avraham Danzig; Kitzur Shulhan Arukh 17:1 of R. Shlomo Ganzfried, Chesed La'alafim 58:5 of R. Eliezer Papo; Shiltei ha-Gibborim 58:3 of Joshua Boaz ben Simon Baruch; Rav Poalim (Orach Chaim 2:2); Shalmei Tzibbur 93c of R. Yisrael Ya'akov Algazi, among others. Rabbi Yechiel Michel Tukachinsky in Sefer Eretz Yisrael (p. 18:3) has written that the custom of the Land of Israel is to follow the Magen Avraham and only under extenuating circumstances may one rely on the Vilna Gaon.
↑ Bi'urei ha-Gra ("Elucidations of the Gra") §459:2
