Armstrong, A. K.; Mamet, B. L. (1978). Carboniferous microfacies, microfossils, and corals, Lisburne Group, Arctic Alaska. US Geological Survey Professional Paper, report. 849[1977]: 1-144.
Professional Paper 849 ("Carboniferous microfacies, microfossils, and corals, Lisburne Group, Arctic Alaska", https://doi.org/10.3133/pp849) appears to have been published in 1977 and released in 1978. On page 20 of volume 1 of "Publications of the U.S. Geological Survey, 1971-1981," (https://doi.org/10.3133/70043706) the Professional Paper 849's citation is: "P 0849. ALASKA. Carboniferous microfacies, microfossils, and corals, Lisburne Group, Arctic Alaska, by A. K. Armstrong and B. L. Mamet. 1977 (1978). 144 p.; plates in pocket". The two years in the citation are explained in the USGS Suggestions to Authors (https://doi.org/10.3133/70058738) on formatting bibliographic citations (on page 77): https://pubs.usgs.gov/unnumbered/70058738/report.pdf . This is further clarified in the next edition of the USGS Suggestions to Authors (https://doi.org/10.3133/7000088) (on page 237): https://pubs.usgs.gov/msb/7000088/report.pdf Courtesy of the USGS Publications Warehouse Team.