Hello,
I am trying to reproduce a model conducted in previous studies, and work from there forward. However, the regression of those papers do truncate two independent variables, both at (-1) and (1). The regression looks like; dependent-var independent-var (truncated) and [battery of control variables]

My data looks like the following, stata-version; STATA 14. want to truncate TAXRISK TAXAVOID.

Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input float(TOBINQ TAXRISK TAXAVOID PTROAw VOL_PTROAw)
 534.9625         .          . -.02838538         .
 716.5151         .          . .002406625         .
 940.1655         .          .  .02955219         .
1438.7303         .          .   .0464805         .
1799.5825         .          .    .081883         .
1524.2985  .2117158 -.05773715  .08523285 .21286123
1292.2108 .18533356 -.11306289  .08704758  .3091128
 1531.971 1.6120528 -.16798247  .04276229 .21286123
1917.7026 .15945534  -.1646288  .06368567 .21286123
1816.2937 .12556152  -.1762948  .04258824 .21286123
 2008.303 .11273167  -.2057642  .03846694 .21286123
 2161.308 .09726332  -.1876211  .04787452 .34941465
1716.2954 .15766433  -.3829571 -.02318152  .4452159
 1418.811  .5652186  -.4990783  .04112059 .29196942
2139.8582 .23024587  -.5566085  .05063291 .21286123
 1443.271         .          . -.02707996         .
 1434.441         .          .  .02324767         .
 2794.025         .          .  .06039088         .
 2415.032         .          .  .03506268         .
  2956.32         .          .  .06606981         .
end