"“And it shall come to pass afterward, that I will pour out My Spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions; and also upon the servants and upon the handmaids in those days will I pour out My Spirit. And I will show wonders in the heavens and in the earth, blood, and fire, and pillars of smoke. The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the Lord come. And it shall come to pass, that whosoever shall call on the name of the Lord shall be delivered: For in Mount Zion and in Jerusalem shall be deliverance, as the Lord hath said, and in the remnant whom the Lord shall call.” Joel 2:28-32 . EW 142.1"
"And it shall come to pass afterward, that I will pour out my spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions: And also upon the servants and upon the handmaids in those days will I pour out my spirit. And I will shew wonders in the heavens and in the earth, blood, and fire, and pillars of smoke. The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the Lord come. And it shall come to pass, that whosoever shall call on the name of the Lord shall be delivered: for in mount Zion and in Jerusalem shall be deliverance, as the Lord hath said, and in the remnant whom the Lord shall call."
Ellen White directly references Joel 2:28-32 in this passage.
"This prophecy of Joel, which speaks of the outpouring of the Holy Spirit in the last days, was not all fulfilled at the beginning of the gospel dispensation. This is evident from the wonders in heaven and in earth, introduced in this text, which were to be precursors of “The great and terrible day of the Lord.” though we have had the signs, that terrible day is still in the future. The whole gospel dispensation may be called the last days, but to say that the last days are all 1800 years in the past, is absurd. They reach to the day of the Lord and to the deliverance of the remnant of God's people: “For in Mount Zion and in Jerusalem shall be deliverance, as the Lord hath said, and in the remnant whom the Lord shall call.” EW 142.2"
"And it shall come to pass afterward, that I will pour out my spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions: And also upon the servants and upon the handmaids in those days will I pour out my spirit. And I will shew wonders in the heavens and in the earth, blood, and fire, and pillars of smoke. The sun shall be turned into darkness, and the moon into blood, before the great and the terrible day of the Lord come."
EGW directly references and quotes Joel 2:28-31, interpreting it in the context of the last days and the outpouring of the Holy Spirit. This is an explicit allusion.