Kent, N., R., Edward, S., B.(1996).Fundamentals of differential equation and bondary value problems / R. Kent Nagle, Edward B. Saff (Ed.ke-2).Massachusetts:.
Gaya MLA
Nagle, R., Kent., Saff, B., Edward."Fundamentals of differential equation and bondary value problems / R. Kent Nagle, Edward B. Saff".Ed.ke-2Massachusetts:,1996.Textbook.