How do you get a monster bone plus in monster hunter freedom

The only way I could get one, I now have four, is by going into the guild and picking the 4 star ranked (LAND SHARK) mission. when i got there all I did was mined for ore killed a small picine then proceeded to destroy the chephadrome. the first time I didnt do all of that I stopped getting Monster bone pluses... so you might want to keep in the rythem. I also got one by doing (THE JUNGLE MENACE) mission in the guild as well. But there I traded 6 Cephelos fins with the old guy in area 5 the killed the KUT KU.