<s>
The	O
Peterson	B-General_Concept
Field	I-General_Concept
Guides	I-General_Concept
(	O
PFG	O
)	O
are	O
a	O
popular	O
and	O
influential	O
series	O
of	O
American	O
field	O
guides	O
intended	O
to	O
assist	O
the	O
layman	O
in	O
identification	O
of	O
birds	O
,	O
plants	O
,	O
insects	O
and	O
other	O
natural	O
phenomena	O
.	O
</s>
<s>
His	O
inaugural	O
volume	O
was	O
the	O
classic	O
1934	O
book	O
A	O
Field	B-General_Concept
Guide	I-General_Concept
to	I-General_Concept
the	I-General_Concept
Birds	I-General_Concept
,	O
published	O
(	O
as	O
were	O
all	O
subsequent	O
volumes	O
)	O
by	O
the	O
Houghton	O
Mifflin	O
Company	O
.	O
</s>
<s>
PFG	O
8	O
:	O
A	O
Field	B-General_Concept
Guide	I-General_Concept
to	I-General_Concept
the	I-General_Concept
Birds	I-General_Concept
of	O
Britain	O
and	O
Europe	O
(	O
1954	O
)	O
,	O
by	O
Roger	O
Tory	O
Peterson	O
,	O
Guy	O
Mountfort	O
,	O
and	O
P.A.D.	O
</s>
<s>
Appweavers	O
,	O
Inc.	O
,	O
the	O
licensee	O
of	O
the	O
Peterson	B-General_Concept
field	I-General_Concept
guides	I-General_Concept
for	O
mobile	O
devices	O
,	O
has	O
developed	O
the	O
Peterson	O
Birds	O
of	O
North	O
America	O
and	O
Peterson	O
Feeder	O
Birds	O
of	O
North	O
America	O
apps	O
for	O
mobile	O
Apple	O
products	O
.	O
</s>
<s>
The	O
Peterson	O
Birds	O
of	O
North	O
America	O
app	O
also	O
includes	O
some	O
content	O
from	O
other	O
books	O
in	O
the	O
Peterson	B-General_Concept
field	I-General_Concept
guide	I-General_Concept
series	O
.	O
</s>
