Consider a 2-dimensional smooth projective algebraic surface S over complex numbers. Could you recommend any exact references to the proofs of the following assertions (of course, if they are true):
If S is rationally chain connected then S is rational.
If through each point of S one can draw a rational curve then S is uniruled.
If S is uniruled then S is ruled.
Recall that a surface is rationally chain connected, through each generic pair of points can be joined by a chain of rational curves on the surface. A uniruled surface is the one which admits a dominant map from $X\times \mathbb{P}^1$ for some curve $X$. A ruled surface is the one which admits a birational map from $X\times \mathbb{P}^1$ for some curve $X$.
Assertion 1 = [1,Proposition IV.3.6] + [1,Theorem IV.3.10] + [1,Proposition IV.3.3.1] + [1,Excercise IV.3.3.5], the latter given without proof. Cf. [1, Excercise IV.3.12.2]. Although this approach seems to be an overkill.
[1] J. Kollar, Rational curves on algebraic varieties, Springer-Verlag, Berlin–Heidelberg, 1996.