This paper outlines our modified method of mass-marking honey bees in observation hives. Our method is inexpensive and widely applicable to research on honey bees, and other pollinators.
Bonoan, R. E., & Starks, P. T. (2016). Observation Hive Marking Apparatus (OHMA): an inexpensive method for mass-marking honey bees in observation hives. Bee World, 93(1), 7-10. doi:10.1080/0005772X.2016.1205327