Names on the publisher page
Besides Were, Lumumba, Sibi-Okumu and Seroney the Open Library list includes Koigi wa Wamwere, Hilary Ng’weno, Barrack Muluka, Wanyiri Kihoro, Mwangi Ruheni, Mude Dae Mude, G. M. Gona, John Roger Kurtz, Kemoli Amata, Anzetse Were, Arthur Andambi, Ibrahim Omondi, Swaleh Mdoe, Joan Sikand, Diana Pitcher, Betty Muthoni Gikonyo, Simeon Nyachae and the Association of East African Cartoonists.
A name on a publisher page is a cataloguing fact, not a current contract.