APA
Usill G., Hearn G. S., . (1946). Practical surveying: a text-book for students preparing for examinations or for survey work in the colonies. London: Technical Press.
Chicago
Usill G.W, Hearn Gordon Sir, . 1946. Practical surveying: a text-book for students preparing for examinations or for survey work in the colonies. London: Technical Press.
Harvard
Usill G., Hearn G. S., . (1946). Practical surveying: a text-book for students preparing for examinations or for survey work in the colonies. London: Technical Press.
MLA
Usill G.W, Hearn Gordon Sir, . Practical surveying: a text-book for students preparing for examinations or for survey work in the colonies. London: Technical Press. 1946.