(a) the owners of twenty percent or more of the area of land included in such proposed change; or

(b) the owners of twenty percent or more of the area of land immediately adjacent to that land included in such proposed change, extending one hundred feet therefrom; or

(c) the owners of twenty percent or more of the area of land directly opposite thereto, extending one hundred feet from the street frontage of such opposite land. The provisions of the previous section relative to public hearings and official notice shall apply equally to all proposed amendments. 2. Amendments made to any zoning ordinance (excluding any map incorporated therein) adopted pursuant to the provisions of this chapter shall be entered in the minutes of the town board; such minutes shall describe and refer to any map adopted in connection with such change, amendment or supplement and a copy, summary or abstract thereof (exclusive of any map incorporated therein) shall be published once in a newspaper published in the town, if any, or in such newspaper published in the county in which such town may be located having a circulation in such town, as the town board may designate, and affidavits of the publication thereof shall be filed with the town clerk. Such ordinance shall take effect upon filing in the office of the town clerk. Every town clerk shall maintain every map adopted in connection with a zoning ordinance or amendment.