Here are instructional resources for searching for grey literature.

Canada

Grey Matters: a Practical Tool for Searching Health-Related Grey Literature [Canadian Association for Drugs and Technologies in Health, CADTH]
https://cadth.ca/resources/finding-evidence/grey-matters

Search for Grey Literature [University of Alberta] [WEBINAR]
https://era.library.ualberta.ca/files/4j03d249k/Copy%20of%202016-02%20NAHLA-searching%20Grey%20Literature.pptx.pdf

Finding Grey Literature (guide) [McMaster University] [LIBGUIDE]
https://hslmcmaster.libguides.com/greylit

Grey Literature: What is It? How to Find Grey Literature [Royal Roads University] [LIBGUIDE]
http://libguides.royalroads.ca/greylit/finding

Grey Literature: What it is & How to Find it [Simon Fraser University]
https://www.lib.sfu.ca/help/research-assistance/format-type/grey-literature

United Kingdom

Finding Grey Literature – Online Webinar [University of Leicester]
https://www2.le.ac.uk/library/help/workshops/events/finding-grey-literature-online-webinar

Searching for Grey Literature [University of Nottingham]
https://www.youtube.com/watch?v=oacg1URjkD4

Search Tools for Grey Literature [University College London]
http://www.ucl.ac.uk/ich/support-services/library/resources-a-to-z/grey-literature

Guide to Search Grey Literature [University of Wolverhampton]
https://www.wlv.ac.uk/lib/media/departments/lis/skills/study-guides/LS124-Searching-Grey-Literature.pdf

United States

Finding SciTech Grey Literature Information [Rocky Mountain Chapter SLA Virtual Lunch]
https://www.slideshare.net/vonhendy/finding-sci-tech-grey-literature-information

Comprehensive Searching – Searching the Grey Literature [Alverno College] https://www.alverno.edu/media/alvernocollege/library/pdfs/grey.pdf

Advanced Information Sources Module 9: Grey Literature [Eduscapes] https://eduscapes.com/cluster/