TY - BOOK ID - 136029858 TI - Summary of available data from the monarch overwintering colonies in Central Mexico, 1976-1991 AU - Zylstra, Erin R. AU - Geological Survey (U.S.) AU - U.S. Fish and Wildlife Service. PY - 2021 PB - Reston, Virginia : U.S. Department of the Interior, U.S. Geological Survey, DB - UniCat KW - Monarch butterfly KW - Butterflies KW - Monitoring KW - Migration UR - https://www.unicat.be/uniCat?func=search&query=sysid:136029858 AB - ER -