There several ways to find curriculum/lesson plans:
From ERIC*: Click HERE to get a list of last 20 years of Curriculum/Teaching Strategy/Lesson Plans (customized search set in ERIC).
From CSUDH OneSearch: Click HERE to get a list of last 20 years of articles, books/eBooks, and reports (Customized search in OneSearch, including: 4692 article, 182 book/eBooks, and 208 reports).
From GoogleScholar: Click HERE to get a list of last 20 years of articles, books/eBook (Customized search in GoogleScholar)
From Government Web sites:
WWC for curriculum/teaching strategy materials evaluations: https://ies.ed.gov/ncee/wwc/FWW
Lesson plans aligned with Common Core: https://achievethecore.org/ (this site is run by the lead writers of the Common Core Standards)
Library of Congress lesson plans: http://www.loc.gov/teachers/?PHPSESSID=86f9a9cc9d66c8b7a2ad93101215d0c2
NEA has some lesson plans available for free: http://www.nea.org/tools/BrowseAllLessons.html
NCTM has some free math lesson plans: https://www.nctm.org/ARCs/
NSF has some science ones: https://www.nsf.gov/news/classroom/