GTA IV mission problem (Chapter III)

[komtugeder]

hello im new here, now im playing gta iv again. i dont have other games so i play this again lol,

im in chapter three now, but now i dont have any missions left. i accomplished jimmy's, phil's, ray's, bernie's and gambetti's mission but i think i missed derrick's mission : Tunnel of Death, frankie's Blood Brothers and Undertaker, gerry's I'll Take Her, She's A Keeper and Diamonds are a Girl's Best Friend, and Ransom.

now i dont have any left mission at radar. i tried to call all of the contacts in the phonebook but nothing happened. so what can i do now ?

thx and sorry for my bad english anyway