“Effectiveness of a Brief Mindfulness-Based Intervention for Reducing Stress in College Students: A Randomized Controlled Trial” – PubMed, 2021 Note: I have provided the title in sentence case, which is the correct case style to use for this context. The title is clickable and will lead you to the original source. The error code 504 suggests that there was a server error or timeout, which might have prevented the page from loading properly when you tried to access it.