Welch, W. W. (1971). A summary of research in science education for the years of 1968-69 secondary school level. ERIC.
Chicago-referens (17:e uppl.)Welch, Wayne W. A Summary of Research in Science Education for the Years of 1968-69 Secondary School Level. Ohio, Estados Unidos: ERIC, 1971.
MLA-referens (9:e uppl.)Welch, Wayne W. A Summary of Research in Science Education for the Years of 1968-69 Secondary School Level. ERIC, 1971.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.