SANTOS, Ma. Arra B..
 Biology Teachers' Systems Thinking Practices and Students' 21st Century Skills: Bases for A Professional Development Model.
<strong>Philippine Journal of Education Studies (formerly the Education Quarterly)</strong>, [S.l.], v. 2, n. 2, p. 95-126, aug. 2025.
ISSN 2984-8180.
Available at: &lt;<a href="https://journals.upd.edu.ph/index.php/pjes/article/view/10773" target="_new">https://journals.upd.edu.ph/index.php/pjes/article/view/10773</a>&gt;. Date accessed: 26 sep. 2025.