\[ \boxed { {x}^{2}{\frac {{\rm d}^{3}}{{\rm d}{x}^{3}}}y \left ( x \right ) +x{\frac {{\rm d}^{2}}{{\rm d}{x}^{2}}}y \left ( x \right ) + \left ( 2\,xy \left ( x \right ) -1 \right ) {\frac {\rm d}{{\rm d}x}}y \left ( x \right ) + \left ( y \left ( x \right ) \right ) ^{2}-f \left ( x \right ) =0} \]
Mathematica: cpu = 0.087511 (sec), leaf count = 41 \[ \text {DSolve}\left [-f(x)+x^2 y^{(3)}(x)+x y''(x)+(2 x y(x)-1) y'(x)+y(x)^2=0,y(x),x\right ] \]
Maple: cpu = 0.406 (sec), leaf count = 60 \[ \left \{ y \left ( x \right ) ={\it ODESolStruc} \left ( {\it \_b} \left ( {\it \_a} \right ) ,[ \left \{ {{\it \_a}}^{2}{\frac {{\rm d}^{2 }}{{\rm d}{{\it \_a}}^{2}}}{\it \_b} \left ( {\it \_a} \right ) +{\it \_a}\, \left ( {\it \_b} \left ( {\it \_a} \right ) \right ) ^{2}-{\it \_a}\,{\frac {\rm d}{{\rm d}{\it \_a}}}{\it \_b} \left ( {\it \_a} \right ) -\int \!f \left ( {\it \_a} \right ) \,{\rm d}{\it \_a}+{\it \_C1}=0 \right \} , \left \{ {\it \_a}=x,{\it \_b} \left ( {\it \_a} \right ) =y \left ( x \right ) \right \} , \left \{ x={\it \_a},y \left ( x \right ) ={\it \_b} \left ( {\it \_a} \right ) \right \} ] \right ) \right \} \]