The happy Trio primers were widely used in Victorian Primary School (c1960s).Blue hard covered book of 96 pages. The book is divided into two parts. Part one is teacher instructions, and part two is a copy of the 'Happy Trio' Reading Scheme primer. Bookplate - "Mary Egan Memorial Collection - Miss Mary Egan, who died on April 4, 1981, spent 23 years as a greatly-respected lecturer in English Curriculum at the Ballarat Teachers' College, the SCV Ballarat, and Ballarat CAE.'reading, happy trio, mary egan, egan, ballarat teachers' college, ballarat college of advanced education, ballarat university college.