for the crescent moon being the same symbol, carrying over from Sin and other pre-islamic sources to islam: The Hymns and Prayers to the Moon-God, Sin, Austin Potts, 1971, p. 14-21

for Ali-Ilah/Allah being the same basic title and being applied originally to the moon god, Carleton S. Coon, Southern Arabia, 1944, p. 399.

Al-Kindi (801-873) in one of the early Christian/Muslim debates traced Allah to the moon god (Three Early Christian-Muslim Debates, ed. by N.A. Newman, 1994, pp. 357, 413, 426)

The editor, Newman, used that to conclucde that Islam is a separate and antagonistic religion which had sprung from idolatry." That might be a bit biased, but he concl;uded it based on the early debates.

"Islam" was a pre-existing term before Muhammad, original;y meaning "sublime virtue, defiance of death, and heroism." (M. Beavmann, The Spiritual Background of Early Islam, 1972, lost the page number).

The Kabah in Mecca preexisting Islam 0 Chamber's Encyclopedia, Encyclopedia Britannica, etc. It's a known fact.

Ramadan matching the Sabean rite of fasting (same time of year, same traditions, same observations) existed up to Islam, and then was immediately repalced by Ramadan, Encyclopedia of Religion (ed. Eliade), 1:324-365, 7:303, 8:225ff)

"Allah is a pre-islamic name, correspondfing to the Babylonian Bel" (Encyclopedia of Religion, 1:1117

C. Montgomery Watt, Profesor of Arabic and Islamic Studies at Edinburgh and visiting professor of Islamic studies at College de France, Georgetown University, and UNiversty of Toronto: "In recent years I have become increasingly convinced that for an adequate understanding of the career of Muhammad and the origins of Islam great importance must be attached to the existence in Mecca of belief in Allah as a "high god."  In a sense this is a form of paganism, but it is so different from paganism as commonly understood that it deserves separate treatment." (Watt, Muhammad's Mecca, p. vii)

Yusuf Ali, Islamic Scholar who translated the Qur'an into english (following is from The Forms of Pagan Worship, pgs. 1619-1623):

"It will be noticed that the sun and the moon and the five planets got identified with a living deity, god or goddesses, with the qualities of its own."

"Moon worship was equally popular in various forms..."

"It maybe noted that the moon was a male Divinity in India, it was also a male Divinity in ancient Semitic religion, and the Arabic word for the moon (qamar) is of the masculine gender."

"The Pagan deities best known in the Ka'ba and round baout Mecca were Lat, uzza, and Manat... they were all female goddesses."
(Note: Al-Lat Al-Uzza and Manat are the "Daughters of Allah, mentioned in the Qur'an (Surah 53:19-23).

Encyclopedia of Religion and Ethics, 1:664: "In any case it is an extremely important fact that Muhammad did not find it necessary to introduce an latogether novel deity, but contented himself with ridding the heathen Allah of his companiosn subjecting him to a kind of dogmatic puriofication."

Encyclopedia of Islam 1:302: "Allah was known to the pre-Islamic Arabs. He was one of the mEccan deities."

ibid., 2:1093: "Ilah...appears in pre-Islamic poetry...By frequency of usage, al-ilah was contracted to allah, frequently attested to in pre-Islamic poetry."

Oxford Dictionary of WOrld Religions, p. 48, "Allah: before the birth of Muhammad, Allah was known as a supreme, but not sole, God."

A short history of Philosophy (Oxford University press), p. 130: "Before Islam, the religions of the Arabic world involvedthe worship of many spirits, called jinn.  Allah was but one of many ghods worshipped in Mecca. But then Muhammad taught the worship of Allah as the only God, whom he identified as the same God worshipped by Christians and Jews."

The Oxford Encyclopedia of the Modern Islamic World, ed. John L. Esposito, 1995: pp. 76-77: "Muhammad's father was named 'Abd Allah' ("Servant of Allah" - and was obviously of central importance in Mecca, where the building called theKa'Bah was indisputably his house... It seems equally certain that Allah was not merely a god in Mecca but was widely regarded as the "high god," the chief and head of the Meccan pantheon..."

Carl Brockerman, History of the ISlamic Peoples, ppo. 8-10: A really long quote, but it describes the roots of all of the traditions and ceremonies in the Pilgrimage to Mecca, showing their pre-Islamic roots

Studies on Islam, trans. and ed. by Mertin L. Swartz (1981), p. 7: "According to D. Neilsen, the starting point of the religion of the Semitic nomads was marked by the astral triad, Sun-Moon_Venus, the moon being more improtant for the nomads and the sun more important for the settled tribes."