SCHULLER ROBERT H. (1991). BE HAPPY ATTITUDES: 8 POSITIVE ATTITUDES THAT CAN TRANSFORM YOUR LIFE. BANTAM BOOKS.
Chicago-viite (17. p.)SCHULLER ROBERT H. BE HAPPY ATTITUDES: 8 POSITIVE ATTITUDES THAT CAN TRANSFORM YOUR LIFE. NEW YORK: BANTAM BOOKS, 1991.
MLA-viite (9. p.)SCHULLER ROBERT H. BE HAPPY ATTITUDES: 8 POSITIVE ATTITUDES THAT CAN TRANSFORM YOUR LIFE. BANTAM BOOKS, 1991.
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