https://launchpad.net/~myriadrf/+archive/ubuntu/gnuradio?field.series_filter=xenial
3.7.10.1 was released on Aug 14, 2016. Is there anything blocking a more recent version of gnuradio?
The document is written before later releases of ubuntu.
Al tough this is more a Ubuntu / gnuradio related question, hope this helps
See the current gnuradio versions for ubuntu https://packages.ubuntu.com/search?keywords=gnuradio
3.7.13.4 is the current release on Github https://github.com/gnuradio/gnuradio
GNU Radio PPA packages are very recent, 3.7.11 was released 2 years ago
|gnuradio - 3.7.11-10~ubuntu17.10.1~ppa2|(changes file)|alexc|2018-03-07|Published|Artful|Comm|All builds were built successfully.|
|---|---|---|---|---|---|---|---|
| gnuradio - 3.7.10.1-2~ubuntu16.10.1~ppa1|(changes file)|alexc|2017-01-31|Published|Yakkety|Comm|All builds were built successfully.|
| gnuradio - 3.7.10.1-2~ubuntu16.04.1~ppa7|(changes file)|alexc|2018-03-07|Published|Xenial|Comm|All builds were built successfully.|