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. Marathon-ka ragga wuxuu ku dhammeeyey kaalinta 94-aad 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. Orodkii ugu dambeeyay ee Zeferino wuxuu ahaa
Marathon ciyaarihii Athens 2004 halkaasoo da'diisu ahayd 38 sano, wuxuu ku dhamaaday kaalinta 78aad waqtigiisa 2:36:22.