Gaya APA
Piskurich, G, M. (1993).
Self-directed learning a practical guide to design, development, and implimentation .
San Francisco:
Jossey-Bass.
Gaya MLA
Piskurich, George, M..
"Self-directed learning a practical guide to design, development, and implimentation".
San Francisco:
Jossey-Bass,
1993.
Buku.