TY - BOOK TI - Bulletin VL - 21 (1936-1941) UR - https://www.biodiversitylibrary.org/item/53310 PB - State of Illinois, Dept. of Registration and Education, Natural History Survey Division CY - Urbana PY - 1936 SN - 0073-4918 N1 - Each issue has also a distinctive title. --- Biological abstracts | 0006-3169 --- Life sciences collection --- Chemical abstracts | 0009-2258 AU - Illinois. Natural History Survey Division KW - Illinois KW - Natural history ER -