Buuxi weedha soo socota: Zeferino, oo saddex jeer ku guuleystay ciyaaraha Olombikada, ayaa markii ugu horreysay u tartamay Cape Verde kulan ka dhacay Maia, Portugal isagoo dhigay rikoor qaran oo ah 3000 mitir oo dabaq ah oo weli taagan maanta. Sannadkii xigay ee 1996-kii Olombikada Xagaaga ee Atlanta, Zeferino wuxuu taariikh u sameeyay Henry Andrade iyo Isménia do Frederico iyagoo noqday ciyaartooydii ugu horreysay ee matalaya qarankan yar ee Afrikaanka ah ee Ciyaaraha Olombikada. Waxaa ku
orodka orodka dheer ee ragga wuxuu ku dhamaaday kaalinta 94aad wakhti dhan 2:34:13. Sannadkii xigay wuxuu ku tartamay 1997 World Championships, isagoo kaalinta 37-aad ka galay marathon-ka isagoo leh waqti dhan 2:25:56. Laba sano ka dib bishii Febraayo 1999, Zeferino wuxuu diiwaan geliyay waqtigiisii ugu fiicnaa abid ee marathon-ka ee Sevilla Marathon oo ku dhammaaday 2:23:16. Lix bilood ka dib tartankii 1999-kii, wuxuu marathon-ka ku dhammeeyey 2:26:03 taasoo ka dhigtay booska 39-aad. Ciyaaraha Olombikada Xagaaga ee 2000 ee Sydney, Zeferino wuxuu hagaajiyay waqtiga iyo booska laga soo bilaabo afar sano ka hor isagoo ka gudbay xariiqda 67-aad waqtigii 2:29:46. Sannadkii xigay, wuxuu ku soo dhamaaday 2001 World Championships, halkaas oo uu ku dhammeeyay marathon-ka kaalinta 51-aad 2:32:46. Tartankii ugu dambeeyay ee Zeferino wuxuu ahaa tartankii marathon-ka ee ciyaarihii Athens 2004 halkaas oo uu 38 jir ahaa, wuxuu ku dhammeeyay 78-aad isagoo leh waqti dhan 2:36:22.