APA (7th ed.) Citation

Stewart, I. A. (1987). A parallel algorithm to four-colour a perfect planar graph.

Chicago Style (17th ed.) Citation

Stewart, Iain A. A Parallel Algorithm to Four-colour a Perfect Planar Graph. Newcastle upon Tyne, 1987.

MLA (9th ed.) Citation

Stewart, Iain A. A Parallel Algorithm to Four-colour a Perfect Planar Graph. 1987.

Warning: These citations may not always be 100% accurate.