500 : a preliminary report giving details of the planning and pro vision for a comprehensive, two year teaching aids course at University College, Dar- es- Salaam, to cater for 500 students during term time w ith comparable facilities for in-service training in the vacations - Pratt, Charles A. (Dar- es- Salaam : University College, Dar-es- Salaam, Institute o f Education, 1967)