Table:
Method and references	Abbreviation	Program for estimation
Bootstrap kernel density estimator [14, 26]	bootkde	bda R package, bde function, bootkde method
Piecewise cubic Hermite interpolating polynomial [21, 27]	hermite spline	signal R package, interp1 function, pchip method
Spline interpolation with Hyman filter [5, 18, 28]	hyman spline	demography R package, cm.spline function
Iterated conditional expectation kernel density estimator [15, 29]	ickde	ICE R package, ickde function
Penalized composite link model [22]	pclm	R code in Rizzi et al. (2015)

Parse the figure content behind with markdown code: | Method and references | Abbreviation | Program for estimation | 
 | --- | --- | --- | 
 | Bootstrap kernel density estimator [14, 26] | bootkde | bda R package, bde function, bootkde method |


 | Piecewise cubic Hermite interpolating polynomial [21, 27] | hermite spline | signal R package, interp1 function, pchip method | 
 | Spline interpolation with Hyman filter [5, 18, 28] | hyman spline | demography R package, cm.spline function | 
 | Iterated conditional expectation kernel density estimator [15, 29] | ickde | ICE R package, ickde function | 
 | Penalized composite link model [22] | pclm | R code in Rizzi et al. (2015) |