By Hill, Napoleon.
Barcelona Grijalbo 1982 .
409 p. , Translation of: Success through a positive mental attitude. 8425313279

By Hill, Napoleon.
Englewood Cliffs, N. J. Prentice-Hall 1965 .
254 p.

By Hill, Napoleon.
Barcelona Bruguera 1982 , Translation of: Think and grow rich.

By Hill, Napoleon.
Madrid, España Editorial EDAF 1996 .
239 p. , Translation of: Napoleon Hill's keys to success. 23 cm..
84-414-0111-X (pbk.)