Link, Michael. Outdoor education : a manual for teaching in nature's classroom / Michael Link. - Englewood Cliffs, N.J. : Prentice-Hall, c1981. - x, 198 p. : ill. ; 24 cm. "A Spectrum book." ISBN: 0136450288 0136450105 (pbk.) LCCN: 81010546 LC Class. No.: LB1047 .L56 1981 / .L56 Dewey Class. No.: 371.3/8