Bhagavad Gita 1-16

anaMtavijayaM raajaa kuMtIputrOyudhiShTiraHa

nakulaHa sahadEvashcha sughOShamaNipushpakou ||16||

"The son of Kunti, king Yudhishtira blew his conch named Anantavijaya where as Nakula and Sahadeva blew Sughosha and Manipushpaka respectively."

 Of the five Pandavas the two got mentioned in the previous shloka. In this one the author mentions the other three Pandavas. Pandu had two wives Kunti and Madri. Yudhishtira, Bhima and Arjuna were sons of Kunti where as Nakula and Sahadeva were the children of Madri. After the death of king Pandu, Madri ends her life in his pyre and Kunti looks after all the five Pandavas (without any discrimination). Thus the author mentions here Yudhishtira as the son of Kunti and not the same about Nakula and Sahadeva. Yudhishtiras conch is named as Anantavijaya meaning unending victory. The conches of Nakula and Sahadeva were Sughosha and Manipushpaka respectively.