Go to Google Scholar and copy-paste this exact search string:
"puberty" "sexual education" Netherlands 1991 boys girls
Also try this in Dutch:
"puberteit" "seksuele voorlichting" jongens meisjes 1991
Then filter results by year: 1990–1995 and look for PDF links.
If you want the full referenced report, say “Yes — compile sources and produce full report” and I will retrieve online sources and prepare it.
If you want to find online resources that mirror the Dutch 1991 standard, ensure they cover the following topics for both genders:
The most relevant known research from that period is:
One landmark paper that might match your interest is:
Vogels, T., & Van der Vliet, R. (1991). Jeugd en seksualiteit: Gedrag en gezondheidsrisico’s bij scholieren. (Youth and sexuality: Behavior and health risks among students). NISSO, Den Haag.
This study covered puberty knowledge, attitudes, and sex education for both boys and girls (ages 12–18) in Dutch secondary schools.
From later reviews citing the 1991 NISSO study:
