Cupillari, Antonella. The nuts and bolts of proofs : an introduction to mathematical proofs / Antonella Cupillari. - 4th ed. - Amsterdam ; Boston : Elsevier Academic Press, c2013. - ix, 283 p. : ill. ; 23 cm. Includes bibliographical references (p. 278-280) and index. ISBN: 9780123822178 Subjects--Topical Terms: Proof theory. LC Class. No.: QA 9.54