TY  - BOOK
AU  - Appel,Kenneth I.
AU  - Haken,Wolfgang
TI  - Every planar map is four colorable
T2  - Contemporary mathematics, 
SN  - 9780821876862 (online)
AV  - QA612.18 .A67 1989
U1  - 511/.5 20
PY  - 1989///
CY  - Providence, R.I.
PB  - American Mathematical Society
KW  - Four-color problem
N1  - Includes bibliographical references; Introduction; Part I: Discharging; Part II: Reducibility; Appendix to Part II; Supplement to Part I; Supplement to Part II; Corresponding Class Check Lists; Access is restricted to licensed institutions; Electronic reproduction; Providence, Rhode Island; American Mathematical Society; 2012
UR  - http://www.ams.org/conm/098/
UR  - http://dx.doi.org/10.1090/conm/098
ER  -