Makala Na Mwandishi Zaidi ya Mawazo YetuMarch 15, 1974Gilbert C. PerlebergMahitaji Yetu Machache, Rahisi na HarakaJune 1, 1972Gilbert C. PerlebergMzeeApril 15, 1971Gilbert C. PerlebergNdiyoFebruary 15, 1971Gilbert C. Perleberg