Positive solutions of singular boundary value problems for systems of nonlinear fourth order differential equations

In this paper, we study the singular boundary value problems for systems of nonlinear fourth order differential equations {u(4)(t)=a1(t)f1(t,u(t),v(t),u″(t),v″(t))+b1(t)g1(t,u(t),v(t),u″(t),v″(t)),v(4)(t)=a2(t)f2(t,u(t),v(t),u″(t),v″(t))+b2(t)g2(t,u(t),v(t),u″(t),v″(t)),0