MLA

MI9, Great Britain. Secret Intelligence Service. Sheet G, Sumatra (South), Java (Extreme North West) ; Sheet H, Borneo (South West), Sumatra (Extreme South), Java (East & West). MI9, 1944. https://collections.library.yale.edu/catalog/15238553.

APA, 6th edition

MI9, G. B. S. I. S. (1944). Sheet G, Sumatra (south), Java (extreme north west) ; Sheet H, Borneo (south west), Sumatra (extreme south), Java (east & west). [Maps, Military maps]. MI9, https://collections.library.yale.edu/catalog/15238553.