Gaya APA
Nagle, R., Saff, E, B. (1993).
Fundamentals of differential equations (3rd edition).
Reading, Mass.:
Addison-Wesley Publishing.
Gaya MLA
Nagle, R.Kent., Saff, Edward, B..
"Fundamentals of differential equations".
3rd edition
Reading, Mass.:
Addison-Wesley Publishing,
1993.
Text.